feat: identity protection UI, duplicate guards, name-lock enforcement (v2.4.6)

- Add password set/change/remove with loading states and double-click prevention
- Add protected identity deletion flow (server-side password removal first)
- Add restore flow for password-protected UUIDs (verify password before saving)
- Add UUID duplicate checks in setUuidForUser (prevent accidental overwrites)
- Add name-locked error handling in launch flow (server enforces registered name)
- Sync shield icon across all identity mutation paths
- Refresh identity dropdown after all password/identity operations
- Propagate force flag through IPC for legitimate overwrites

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -52,12 +52,20 @@ jobs:
         run: |
           RELEASE_ID=$(curl -s "${FORGEJO_API}/repos/${GITHUB_REPOSITORY}/releases/tags/${{ github.ref_name }}" \
             -H "Authorization: token ${{ secrets.RELEASE_TOKEN }}" | python3 -c 'import sys,json; print(json.load(sys.stdin)["id"])')
+          echo "Release ID: ${RELEASE_ID}"
+          echo "Upload URL: ${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets"
           for file in dist/*.exe dist/*.exe.blockmap dist/latest.yml; do
             [ -f "$file" ] || continue
-            echo "Uploading $file..."
-            curl -s --max-time 600 -X POST "${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets?name=$(basename $file)" \
+            echo "Uploading $file ($(stat -c%s "$file" 2>/dev/null || stat -f%z "$file") bytes)..."
+            HTTP_CODE=$(curl -w '%{http_code}' --max-time 600 -X POST "${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets?name=$(basename $file)" \
               -H "Authorization: token ${{ secrets.RELEASE_TOKEN }}" \
-              -F "attachment=@${file}" || echo "Failed to upload $file"
+              -F "attachment=@${file}" -o /tmp/upload_response.txt 2>/tmp/upload_err.txt)
+            if [ "$HTTP_CODE" = "201" ]; then
+              echo "OK — uploaded $(basename $file)"
+            else
+              echo "FAILED (HTTP $HTTP_CODE): $(cat /tmp/upload_response.txt)"
+              echo "Curl stderr: $(cat /tmp/upload_err.txt)"
+            fi
           done
 
   build-macos:
@@ -83,12 +91,19 @@ jobs:
         run: |
           RELEASE_ID=$(curl -s "${FORGEJO_API}/repos/${GITHUB_REPOSITORY}/releases/tags/${{ github.ref_name }}" \
             -H "Authorization: token ${{ secrets.RELEASE_TOKEN }}" | python3 -c 'import sys,json; print(json.load(sys.stdin)["id"])')
+          echo "Release ID: ${RELEASE_ID}"
           for file in dist/*.dmg dist/*.zip dist/*.blockmap dist/latest-mac.yml; do
             [ -f "$file" ] || continue
             echo "Uploading $file..."
-            curl -s --max-time 600 -X POST "${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets?name=$(basename $file)" \
+            HTTP_CODE=$(curl -w '%{http_code}' --max-time 600 -X POST "${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets?name=$(basename $file)" \
               -H "Authorization: token ${{ secrets.RELEASE_TOKEN }}" \
-              -F "attachment=@${file}" || echo "Failed to upload $file"
+              -F "attachment=@${file}" -o /tmp/upload_response.txt 2>/tmp/upload_err.txt)
+            if [ "$HTTP_CODE" = "201" ]; then
+              echo "OK — uploaded $(basename $file)"
+            else
+              echo "FAILED (HTTP $HTTP_CODE): $(cat /tmp/upload_response.txt)"
+              echo "Curl stderr: $(cat /tmp/upload_err.txt)"
+            fi
           done
 
   build-linux:
@@ -113,10 +128,17 @@ jobs:
         run: |
           RELEASE_ID=$(curl -s "${FORGEJO_API}/repos/${GITHUB_REPOSITORY}/releases/tags/${{ github.ref_name }}" \
             -H "Authorization: token ${{ secrets.RELEASE_TOKEN }}" | python3 -c 'import sys,json; print(json.load(sys.stdin)["id"])')
+          echo "Release ID: ${RELEASE_ID}"
           for file in dist/*.AppImage dist/*.AppImage.blockmap dist/*.deb dist/*.rpm dist/*.pacman dist/latest-linux.yml; do
             [ -f "$file" ] || continue
-            echo "Uploading $file..."
-            curl -s --max-time 600 -X POST "${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets?name=$(basename $file)" \
+            echo "Uploading $file ($(stat -c%s "$file" 2>/dev/null || stat -f%z "$file") bytes)..."
+            HTTP_CODE=$(curl -w '%{http_code}' --max-time 600 -X POST "${FORGEJO_UPLOAD}/repos/${GITHUB_REPOSITORY}/releases/${RELEASE_ID}/assets?name=$(basename $file)" \
               -H "Authorization: token ${{ secrets.RELEASE_TOKEN }}" \
-              -F "attachment=@${file}" || echo "Failed to upload $file"
+              -F "attachment=@${file}" -o /tmp/upload_response.txt 2>/tmp/upload_err.txt)
+            if [ "$HTTP_CODE" = "201" ]; then
+              echo "OK — uploaded $(basename $file)"
+            else
+              echo "FAILED (HTTP $HTTP_CODE): $(cat /tmp/upload_response.txt)"
+              echo "Curl stderr: $(cat /tmp/upload_err.txt)"
+            fi
           done

GUI/index.html

@@ -73,22 +73,41 @@
                     <span id="onlineCount" class="counter-value">0</span>
                 </div>
 
+                <div class="identity-selector" id="identitySelector">
+                    <button class="identity-btn" onclick="toggleIdentityDropdown()">
+                        <i class="fas fa-id-badge"></i>
+                        <span id="currentIdentityName">Player</span>
+                        <i id="passwordShieldIcon" class="fas fa-unlock password-shield unprotected" data-tooltip="Click to protect identity" onclick="event.stopPropagation(); openPasswordModal()"></i>
+                        <i class="fas fa-chevron-down"></i>
+                    </button>
+                    <div class="identity-dropdown" id="identityDropdown">
+                        <div class="identity-list" id="identityList"></div>
+                        <div class="identity-divider"></div>
+                        <div class="identity-action" onclick="openIdentityManager()">
+                            <i class="fas fa-fingerprint"></i>
+                            <span data-i18n="header.manageIdentities">Manage</span>
+                        </div>
+                    </div>
+                    <span class="header-tooltip" data-i18n="header.identityTooltip">Your player name &amp; UUID used in-game</span>
+                </div>
+
                 <div class="profile-selector" id="profileSelector">
                     <button class="profile-btn" onclick="toggleProfileDropdown()">
-                        <i class="fas fa-user-circle"></i>
+                        <i class="fas fa-sliders-h"></i>
                         <span id="currentProfileName">Default</span>
                         <i class="fas fa-chevron-down"></i>
                     </button>
                     <div class="profile-dropdown" id="profileDropdown">
                         <div class="profile-list" id="profileList">
-                            <!-- Profiles populated by JS -->
+                            <!-- Configurations populated by JS -->
                         </div>
                         <div class="profile-divider"></div>
                         <div class="profile-action" onclick="openProfileManager()">
                             <i class="fas fa-cog"></i>
-                            <span data-i18n="header.manageProfiles">Manage Profiles</span>
+                            <span data-i18n="header.manageProfiles">Manage</span>
                         </div>
                     </div>
+                    <span class="header-tooltip" data-i18n="header.configTooltip">Game config: mods, Java &amp; memory settings</span>
                 </div>
 
                 <div class="window-controls">
@@ -574,6 +593,18 @@
                                                 </div>
                                             </label>
                                         </div>
+                                        <div class="settings-option">
+                                            <label class="settings-checkbox">
+                                                <input type="checkbox" id="allowMultiInstanceCheck" />
+                                                <span class="checkmark"></span>
+                                                <div class="checkbox-content">
+                                                    <div class="checkbox-title" data-i18n="settings.allowMultiInstance">Allow multiple game instances</div>
+                                                    <div class="checkbox-description" data-i18n="settings.allowMultiInstanceDescription">
+                                                        Allow running multiple game clients at the same time (useful for mod development)
+                                                    </div>
+                                                </div>
+                                            </label>
+                                        </div>
                                         <div class="settings-option">
                                             <label class="settings-checkbox">
                                                 <input type="checkbox" id="launcherHwAccelCheck" />
@@ -736,28 +767,40 @@
             </div>
 
             <div class="uuid-modal-body">
-                <div class="uuid-current-section">
-                    <h3 class="uuid-section-title" data-i18n="uuid.currentUserUUID">Current User UUID</h3>
-                    <div class="uuid-current-display">
-                        <input type="text" id="modalCurrentUuid" class="uuid-display-input" readonly />
-                        <button id="modalCopyUuidBtn" class="uuid-action-btn copy-btn" title="Copy UUID">
-                            <i class="fas fa-copy"></i>
-                        </button>
-                        <button id="modalRegenerateUuidBtn" class="uuid-action-btn regenerate-btn"
-                            title="Generate New UUID">
-                            <i class="fas fa-sync-alt"></i>
-                        </button>
-                    </div>
-                </div>
-
                 <div class="uuid-list-section">
                     <div class="uuid-list-header">
                         <h3 class="uuid-section-title" data-i18n="uuid.allPlayerUUIDs">All Player UUIDs</h3>
-                        <button id="generateNewUuidBtn" class="uuid-generate-btn">
+                        <button id="addIdentityBtn" class="uuid-generate-btn">
                             <i class="fas fa-plus"></i>
-                            <span data-i18n="uuid.generateNew">Generate New UUID</span>
+                            <span data-i18n="uuid.addIdentity">Add Identity</span>
                         </button>
                     </div>
+                    <div id="uuidAddForm" class="uuid-add-form" style="display: none;">
+                        <div class="uuid-add-form-row">
+                            <input type="text" id="addIdentityUsername" class="uuid-input"
+                                data-i18n-placeholder="uuid.usernamePlaceholder"
+                                placeholder="Username" maxlength="16" />
+                        </div>
+                        <div class="uuid-add-form-row">
+                            <input type="text" id="addIdentityUuid" class="uuid-input"
+                                data-i18n-placeholder="uuid.customPlaceholder"
+                                placeholder="UUID (auto-generated)" maxlength="36" />
+                            <button id="addIdentityRegenerateBtn" class="uuid-action-btn regenerate-btn"
+                                title="Generate new UUID">
+                                <i class="fas fa-sync-alt"></i>
+                            </button>
+                        </div>
+                        <div class="uuid-add-form-actions">
+                            <button id="addIdentityConfirmBtn" class="uuid-set-btn">
+                                <i class="fas fa-check"></i>
+                                <span data-i18n="uuid.add">Add</span>
+                            </button>
+                            <button id="addIdentityCancelBtn" class="uuid-cancel-btn">
+                                <i class="fas fa-times"></i>
+                                <span data-i18n="uuid.cancel">Cancel</span>
+                            </button>
+                        </div>
+                    </div>
                     <div id="uuidList" class="uuid-list">
                         <div class="uuid-loading">
                             <i class="fas fa-spinner fa-spin"></i>
@@ -766,21 +809,62 @@
                     </div>
                 </div>
 
-                <div class="uuid-custom-section">
-                    <h3 class="uuid-section-title" data-i18n="uuid.setCustomUUID">Set Custom UUID</h3>
-                    <div class="uuid-custom-form">
-                        <input type="text" id="customUuidInput" class="uuid-input"
-                            data-i18n-placeholder="uuid.customPlaceholder" maxlength="36" />
-                        <button id="setCustomUuidBtn" class="uuid-set-btn">
-                            <i class="fas fa-check"></i>
-                            <span data-i18n="uuid.setUUID">Set UUID</span>
-                        </button>
+                <div class="uuid-advanced-section">
+                    <button id="uuidAdvancedToggle" class="uuid-advanced-toggle">
+                        <i class="fas fa-chevron-right uuid-advanced-chevron"></i>
+                        <span data-i18n="uuid.advanced">Advanced</span>
+                    </button>
+                    <div id="uuidAdvancedContent" class="uuid-advanced-content" style="display: none;">
+                        <h3 class="uuid-section-title" data-i18n="uuid.setCustomUUID">Set Custom UUID</h3>
+                        <div class="uuid-custom-form">
+                            <input type="text" id="customUuidInput" class="uuid-input"
+                                data-i18n-placeholder="uuid.customPlaceholder" maxlength="36" />
+                            <button id="setCustomUuidBtn" class="uuid-set-btn">
+                                <i class="fas fa-check"></i>
+                                <span data-i18n="uuid.setUUID">Set UUID</span>
+                            </button>
+                        </div>
+                        <p class="uuid-custom-hint">
+                            <i class="fas fa-exclamation-triangle"></i>
+                            <span data-i18n="uuid.warning">Warning: Setting a custom UUID will change your current player
+                                identity</span>
+                        </p>
+                    </div>
+                </div>
+
+                <div class="uuid-advanced-section" style="margin-top: 12px;">
+                    <button id="passwordSectionToggle" class="uuid-advanced-toggle">
+                        <i class="fas fa-chevron-right uuid-advanced-chevron"></i>
+                        <span>Password Protection</span>
+                    </button>
+                    <div id="passwordSectionContent" class="uuid-advanced-content" style="display: none;">
+                        <h3 class="uuid-section-title">Protect Your Identity</h3>
+                        <p class="uuid-custom-hint" style="margin-bottom: 12px;">
+                            <i class="fas fa-shield-alt"></i>
+                            <span>Set a password to prevent others from using your UUID</span>
+                        </p>
+                        <div id="passwordStatusMsg" class="uuid-custom-hint" style="margin-bottom: 8px; color: #93a3b8;"></div>
+                        <div id="passwordSetForm">
+                            <div class="uuid-custom-form" style="margin-bottom: 8px;">
+                                <input type="password" id="currentPasswordInput" class="uuid-input"
+                                    placeholder="Current password" style="display: none;" />
+                            </div>
+                            <div class="uuid-custom-form" style="margin-bottom: 8px;">
+                                <input type="password" id="newPasswordInput" class="uuid-input"
+                                    placeholder="New password (min 6 chars)" />
+                            </div>
+                            <div class="uuid-custom-form">
+                                <button id="setPasswordBtn" class="uuid-set-btn" onclick="handleSetPassword()">
+                                    <i class="fas fa-lock"></i>
+                                    <span>Set Password</span>
+                                </button>
+                                <button id="removePasswordBtn" class="uuid-cancel-btn" onclick="handleRemovePassword()" style="display: none;">
+                                    <i class="fas fa-unlock"></i>
+                                    <span>Remove Password</span>
+                                </button>
+                            </div>
+                        </div>
                     </div>
-                    <p class="uuid-custom-hint">
-                        <i class="fas fa-exclamation-triangle"></i>
-                        <span data-i18n="uuid.warning">Warning: Setting a custom UUID will change your current player
-                            identity</span>
-                    </p>
                 </div>
             </div>
         </div>
@@ -791,8 +875,8 @@
         <div class="profile-modal-content">
             <div class="profile-modal-header">
                 <h2 class="profile-modal-title">
-                    <i class="fas fa-users-cog mr-2"></i>
-                    <span data-i18n="profiles.modalTitle">Manage Profiles</span>
+                    <i class="fas fa-sliders-h mr-2"></i>
+                    <span data-i18n="configurations.modalTitle">Manage Configurations</span>
                 </h2>
                 <button class="modal-close-btn" onclick="closeProfileManager()">
                     <i class="fas fa-times"></i>
@@ -803,16 +887,69 @@
                     <!-- Populated by JS -->
                 </div>
                 <div class="profile-create-section">
-                    <input type="text" id="newProfileName" data-i18n-placeholder="profiles.newProfilePlaceholder"
+                    <input type="text" id="newProfileName" data-i18n-placeholder="configurations.newProfilePlaceholder"
                         class="profile-input" maxlength="20">
                     <button class="profile-create-btn" onclick="createNewProfile()">
-                        <i class="fas fa-plus"></i> <span data-i18n="profiles.createProfile">Create Profile</span>
+                        <i class="fas fa-plus"></i> <span data-i18n="configurations.createProfile">Create Configuration</span>
                     </button>
                 </div>
             </div>
         </div>
     </div>
 
+    <!-- Password Protection Modal -->
+    <div id="passwordModal" class="uuid-modal" style="display: none;">
+        <div class="uuid-modal-content" style="max-width: 420px;">
+            <div class="uuid-modal-header">
+                <h2 class="uuid-modal-title">
+                    <i class="fas fa-shield-alt mr-2"></i>
+                    <span>Identity Protection</span>
+                </h2>
+                <button class="modal-close-btn" onclick="closePasswordModal()">
+                    <i class="fas fa-times"></i>
+                </button>
+            </div>
+            <div class="uuid-modal-body" style="padding: 16px 20px;">
+                <div style="display: flex; align-items: center; gap: 12px; margin-bottom: 16px; padding: 12px; background: rgba(255,255,255,0.03); border-radius: 8px; border: 1px solid rgba(255,255,255,0.06);">
+                    <i class="fas fa-user" style="color: #22c55e; font-size: 1.2em;"></i>
+                    <div style="flex:1; min-width:0;">
+                        <div id="pwModalName" style="font-weight: 600; font-size: 1em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;">Player</div>
+                        <div id="pwModalUuid" style="font-size: 0.7em; color: #6b7280; font-family: monospace; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;"></div>
+                    </div>
+                    <div id="pwModalStatusBadge" style="flex-shrink:0;"></div>
+                </div>
+
+                <div id="pwModalStatusText" style="margin-bottom: 14px; font-size: 0.85em; color: #93a3b8; text-align: center;"></div>
+
+                <div id="pwModalSetForm">
+                    <div style="margin-bottom: 10px;">
+                        <input type="password" id="pwModalCurrentPassword" class="uuid-input"
+                            placeholder="Current password" style="display: none; width: 100%;" />
+                    </div>
+                    <div style="margin-bottom: 10px;">
+                        <input type="password" id="pwModalNewPassword" class="uuid-input"
+                            placeholder="New password (min 6 chars)" style="width: 100%;" />
+                    </div>
+                    <div style="display: flex; gap: 8px;">
+                        <button id="pwModalSetBtn" class="uuid-set-btn" style="flex:1;" onclick="handlePasswordModalSet()">
+                            <i class="fas fa-lock"></i>
+                            <span>Set Password</span>
+                        </button>
+                        <button id="pwModalRemoveBtn" class="uuid-cancel-btn" style="display: none;" onclick="handlePasswordModalRemove()">
+                            <i class="fas fa-unlock"></i>
+                            <span>Remove</span>
+                        </button>
+                    </div>
+                </div>
+
+                <div id="pwModalUsernameInfo" style="margin-top: 14px; padding: 10px; background: rgba(34,197,94,0.06); border-radius: 6px; border: 1px solid rgba(34,197,94,0.15); font-size: 0.8em; color: #93a3b8; display: none;">
+                    <i class="fas fa-info-circle" style="color: #22c55e;"></i>
+                    <span>Setting a password also reserves your username — no one else can use it.</span>
+                </div>
+            </div>
+        </div>
+    </div>
+
     <div class="version-display-bottom">
         <i class="fas fa-code-branch"></i>
         <span id="launcherVersion"></span>

GUI/js/launcher.js

@@ -35,13 +35,21 @@ export function setupLauncher() {
   // Initial Profile Load
   loadProfiles();
 
-  // Close dropdown on outside click
+  // Initial Identity Load
+  loadIdentities();
+
+  // Close dropdowns on outside click
   document.addEventListener('click', (e) => {
-    const selector = document.getElementById('profileSelector');
-    if (selector && !selector.contains(e.target)) {
+    const profileSelector = document.getElementById('profileSelector');
+    if (profileSelector && !profileSelector.contains(e.target)) {
       const dropdown = document.getElementById('profileDropdown');
       if (dropdown) dropdown.classList.remove('show');
     }
+    const identitySelector = document.getElementById('identitySelector');
+    if (identitySelector && !identitySelector.contains(e.target)) {
+      const dropdown = document.getElementById('identityDropdown');
+      if (dropdown) dropdown.classList.remove('show');
+    }
   });
 }
 
@@ -83,7 +91,7 @@ function renderProfileList(profiles, activeProfile) {
     managerList.innerHTML = profiles.map(p => `
             <div class="profile-manager-item ${p.id === activeProfile.id ? 'active' : ''}">
                 <div class="flex items-center gap-3">
-                    <i class="fas fa-user-circle text-xl text-gray-400"></i>
+                    <i class="fas fa-sliders-h text-xl text-gray-400"></i>
                     <div>
                         <div class="font-bold">${p.name}</div>
                         <div class="text-xs text-gray-500">ID: ${p.id.substring(0, 8)}...</div>
@@ -106,13 +114,6 @@ function updateCurrentProfileUI(profile) {
   }
 }
 
-window.toggleProfileDropdown = () => {
-  const dropdown = document.getElementById('profileDropdown');
-  if (dropdown) {
-    dropdown.classList.toggle('show');
-  }
-};
-
 window.openProfileManager = () => {
   const modal = document.getElementById('profileManagerModal');
   if (modal) {
@@ -146,7 +147,7 @@ window.createNewProfile = async () => {
 };
 
 window.deleteProfile = async (id) => {
-  if (!confirm('Are you sure you want to delete this profile? parameters and mods configuration will be lost.')) return;
+  if (!confirm('Are you sure you want to delete this configuration? Mod settings will be lost.')) return;
 
   try {
     await window.electronAPI.profile.delete(id);
@@ -160,7 +161,7 @@ window.deleteProfile = async (id) => {
 window.switchProfile = async (id) => {
   try {
     if (window.LauncherUI) window.LauncherUI.showProgress();
-    const switchingMsg = window.i18n ? window.i18n.t('progress.switchingProfile') : 'Switching Profile...';
+    const switchingMsg = window.i18n ? window.i18n.t('progress.switchingProfile') : 'Switching configuration...';
     if (window.LauncherUI) window.LauncherUI.updateProgress({ message: switchingMsg });
 
     await window.electronAPI.profile.activate(id);
@@ -179,7 +180,7 @@ window.switchProfile = async (id) => {
     if (dropdown) dropdown.classList.remove('show');
 
     if (window.LauncherUI) {
-      const switchedMsg = window.i18n ? window.i18n.t('progress.profileSwitched') : 'Profile Switched!';
+      const switchedMsg = window.i18n ? window.i18n.t('progress.profileSwitched') : 'Configuration switched!';
       window.LauncherUI.updateProgress({ message: switchedMsg });
       setTimeout(() => window.LauncherUI.hideProgress(), 1000);
     }
@@ -192,7 +193,8 @@ window.switchProfile = async (id) => {
 };
 
 export async function launch() {
-  if (isDownloading || (playBtn && playBtn.disabled)) return;
+  const btn = homePlayBtn || playBtn;
+  if (isDownloading || (btn && btn.disabled)) return;
 
   // ==========================================================================
   // STEP 1: Check launch readiness from backend (single source of truth)
@@ -270,11 +272,7 @@ export async function launch() {
   // STEP 3: Start launch process
   // ==========================================================================
   if (window.LauncherUI) window.LauncherUI.showProgress();
-  isDownloading = true;
-  if (playBtn) {
-    playBtn.disabled = true;
-    playText.textContent = 'LAUNCHING...';
-  }
+  lockPlayButton('LAUNCHING...');
 
   try {
     const startingMsg = window.i18n ? window.i18n.t('progress.startingGame') : 'Starting game...';
@@ -284,20 +282,92 @@ export async function launch() {
       // Pass playerName from config - backend will validate again
       const result = await window.electronAPI.launchGame(playerName, javaPath, '', gpuPreference);
 
-      isDownloading = false;
-
-      if (window.LauncherUI) {
-        window.LauncherUI.hideProgress();
+      if (result.usernameTaken) {
+        // Username reserved by another player
+        isDownloading = false;
+        if (window.LauncherUI) window.LauncherUI.hideProgress();
+        resetPlayButton();
+        if (window.LauncherUI && window.LauncherUI.showError) {
+          window.LauncherUI.showError('This username is reserved by another player. Please change your player name in Identity settings.');
+        } else {
+          showNotification('This username is reserved by another player. Please change your player name.', 'error');
+        }
+        return;
+      }
+
+      if (result.nameLocked) {
+        // UUID is password-protected and locked to a specific name
+        isDownloading = false;
+        if (window.LauncherUI) window.LauncherUI.hideProgress();
+        resetPlayButton();
+        const msg = result.registeredName
+          ? `This UUID is locked to username "${result.registeredName}". Change your identity name to "${result.registeredName}" in Settings.`
+          : 'This UUID is locked to a different username. Check your identity settings.';
+        if (window.LauncherUI && window.LauncherUI.showError) {
+          window.LauncherUI.showError(msg);
+        } else {
+          showNotification(msg, 'error');
+        }
+        return;
+      }
+
+      if (result.passwordRequired) {
+        // Check for saved password first
+        let savedPw = null;
+        try {
+          const cfg = await window.electronAPI.loadConfig();
+          const uuid = result.uuid || '';
+          savedPw = cfg && cfg.savedPasswords && cfg.savedPasswords[uuid] ? cfg.savedPasswords[uuid] : null;
+        } catch (e) { /* ignore */ }
+
+        if (savedPw) {
+          // Try saved password silently
+          if (window.LauncherUI) window.LauncherUI.showProgress();
+          lockPlayButton('LAUNCHING...');
+          const autoResult = await window.electronAPI.launchGameWithPassword(playerName, javaPath, '', gpuPreference, savedPw);
+          if (autoResult.success) {
+            isDownloading = false;
+            if (window.LauncherUI) window.LauncherUI.hideProgress();
+            resetPlayButton();
+            if (window.electronAPI.minimizeWindow) setTimeout(() => { window.electronAPI.minimizeWindow(); }, 500);
+            return;
+          }
+          // Saved password failed — clear it and show popup
+          isDownloading = false;
+          if (window.LauncherUI) window.LauncherUI.hideProgress();
+          resetPlayButton();
+          try {
+            const cfg2 = await window.electronAPI.loadConfig();
+            const sp = cfg2.savedPasswords || {};
+            delete sp[result.uuid || ''];
+            await window.electronAPI.saveConfig({ savedPasswords: sp });
+          } catch (e) { /* ignore */ }
+        }
+
+        // Show interactive password dialog
+        const launchResult = await promptForPasswordAndLaunch(playerName, javaPath, gpuPreference, result.uuid);
+        if (launchResult && launchResult.success) {
+          if (window.electronAPI.minimizeWindow) setTimeout(() => { window.electronAPI.minimizeWindow(); }, 500);
+        }
+        return;
       }
-      resetPlayButton();
 
       if (result.success) {
+        // Keep button locked so user can't double-launch
+        if (window.LauncherUI) window.LauncherUI.hideProgress();
+        lockPlayButton('GAME RUNNING');
+        setTimeout(() => {
+          resetPlayButton();
+        }, 10000); // Reset after 10s (game should be visible by then)
         if (window.electronAPI.minimizeWindow) {
           setTimeout(() => {
             window.electronAPI.minimizeWindow();
           }, 500);
         }
       } else {
+        isDownloading = false;
+        if (window.LauncherUI) window.LauncherUI.hideProgress();
+        resetPlayButton();
         console.error('[Launcher] Launch failed:', result.error);
 
         // Handle specific error cases
@@ -353,6 +423,187 @@ export async function launch() {
   }
 }
 
+function promptForPasswordAndLaunch(playerName, javaPath, gpuPreference, uuid) {
+  return new Promise((resolve) => {
+    // Remove any existing password prompt
+    const existing = document.querySelector('.custom-confirm-modal');
+    if (existing) existing.remove();
+
+    const overlay = document.createElement('div');
+    overlay.className = 'custom-confirm-modal';
+    overlay.style.cssText = `
+      position: fixed;
+      top: 0;
+      left: 0;
+      right: 0;
+      bottom: 0;
+      background: rgba(0, 0, 0, 0.8);
+      backdrop-filter: blur(4px);
+      z-index: 20000;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+    `;
+
+    const dialog = document.createElement('div');
+    dialog.style.cssText = `
+      background: #1f2937;
+      border-radius: 12px;
+      padding: 0;
+      min-width: 380px;
+      max-width: 420px;
+      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
+      border: 1px solid rgba(255, 255, 255, 0.1);
+    `;
+
+    dialog.innerHTML = `
+      <div style="padding: 20px 24px; border-bottom: 1px solid rgba(255,255,255,0.1);">
+        <div style="display: flex; align-items: center; gap: 10px; color: #f59e0b;">
+          <i class="fas fa-lock" style="font-size: 20px;"></i>
+          <h3 style="margin: 0; font-size: 1.1rem; font-weight: 600; color: #e5e7eb;">Password Required</h3>
+        </div>
+      </div>
+      <div style="padding: 20px 24px;">
+        <p style="margin: 0 0 12px 0; color: #9ca3af; font-size: 0.9rem; line-height: 1.5;">This identity is password-protected. Enter your password to continue.</p>
+        <div id="pwErrorMsg" style="display: none; margin-bottom: 12px; padding: 8px 12px; background: rgba(239,68,68,0.15); border: 1px solid rgba(239,68,68,0.3); border-radius: 6px; color: #f87171; font-size: 0.85rem;"></div>
+        <input type="password" id="launchPasswordInput" style="
+          width: 100%;
+          box-sizing: border-box;
+          padding: 10px 14px;
+          background: rgba(0,0,0,0.3);
+          border: 1px solid rgba(255,255,255,0.15);
+          border-radius: 8px;
+          color: #e5e7eb;
+          font-size: 0.95rem;
+          outline: none;
+        " placeholder="Password" autofocus />
+        <label style="display: flex; align-items: center; gap: 8px; margin-top: 12px; cursor: pointer; color: #9ca3af; font-size: 0.85rem; user-select: none;">
+          <input type="checkbox" id="pwRememberCheck" style="accent-color: #f59e0b; width: 16px; height: 16px; cursor: pointer;" />
+          Remember password
+        </label>
+      </div>
+      <div style="padding: 16px 24px; display: flex; gap: 10px; justify-content: flex-end; border-top: 1px solid rgba(255,255,255,0.1);">
+        <button id="pwCancelBtn" style="
+          background: transparent;
+          color: #9ca3af;
+          border: 1px solid rgba(156,163,175,0.3);
+          padding: 9px 18px;
+          border-radius: 6px;
+          cursor: pointer;
+          font-size: 0.9rem;
+        ">Cancel</button>
+        <button id="pwConfirmBtn" style="
+          background: #f59e0b;
+          color: #000;
+          border: none;
+          padding: 9px 18px;
+          border-radius: 6px;
+          cursor: pointer;
+          font-weight: 600;
+          font-size: 0.9rem;
+        ">Login</button>
+      </div>
+    `;
+
+    overlay.appendChild(dialog);
+    document.body.appendChild(overlay);
+
+    const input = overlay.querySelector('#launchPasswordInput');
+    const confirmBtn = overlay.querySelector('#pwConfirmBtn');
+    const cancelBtn = overlay.querySelector('#pwCancelBtn');
+    const errorMsg = overlay.querySelector('#pwErrorMsg');
+    const rememberCheck = overlay.querySelector('#pwRememberCheck');
+
+    let busy = false;
+
+    const close = (result) => {
+      overlay.remove();
+      isDownloading = false;
+      if (window.LauncherUI) window.LauncherUI.hideProgress();
+      resetPlayButton();
+      resolve(result);
+    };
+
+    const showError = (msg) => {
+      errorMsg.textContent = msg;
+      errorMsg.style.display = 'block';
+      input.style.borderColor = 'rgba(239,68,68,0.5)';
+      input.value = '';
+      input.focus();
+    };
+
+    const tryLogin = async () => {
+      const password = input.value;
+      if (!password) {
+        showError('Please enter your password.');
+        return;
+      }
+      if (busy) return;
+      busy = true;
+
+      // Show loading state
+      confirmBtn.disabled = true;
+      confirmBtn.textContent = 'Logging in...';
+      errorMsg.style.display = 'none';
+      input.style.borderColor = 'rgba(255,255,255,0.15)';
+
+      try {
+        if (window.LauncherUI) window.LauncherUI.showProgress();
+        lockPlayButton('LAUNCHING...');
+
+        const result = await window.electronAPI.launchGameWithPassword(playerName, javaPath, '', gpuPreference, password);
+
+        if (result.success) {
+          // Save password if "Remember" checked
+          if (rememberCheck.checked && uuid) {
+            try {
+              const cfg = await window.electronAPI.loadConfig();
+              const sp = cfg.savedPasswords || {};
+              sp[uuid] = password;
+              await window.electronAPI.saveConfig({ savedPasswords: sp });
+            } catch (e) { /* ignore */ }
+          }
+          overlay.remove();
+          isDownloading = false;
+          if (window.LauncherUI) window.LauncherUI.hideProgress();
+          resetPlayButton();
+          resolve(result);
+          return;
+        }
+
+        // Wrong password
+        if (result.passwordRequired) {
+          showError(result.error || 'Incorrect password. Please try again.');
+        } else {
+          showError(result.error || 'Launch failed.');
+        }
+
+        isDownloading = false;
+        if (window.LauncherUI) window.LauncherUI.hideProgress();
+        resetPlayButton();
+      } catch (err) {
+        showError(err.message || 'An error occurred.');
+        isDownloading = false;
+        if (window.LauncherUI) window.LauncherUI.hideProgress();
+        resetPlayButton();
+      } finally {
+        busy = false;
+        confirmBtn.disabled = false;
+        confirmBtn.textContent = 'Login';
+      }
+    };
+
+    confirmBtn.addEventListener('click', tryLogin);
+    cancelBtn.addEventListener('click', () => close(null));
+    input.addEventListener('keydown', (e) => {
+      if (e.key === 'Enter') tryLogin();
+      if (e.key === 'Escape') close(null);
+    });
+
+    setTimeout(() => input.focus(), 100);
+  });
+}
+
 function showCustomConfirm(message, title, onConfirm, onCancel = null, confirmText, cancelText) {
   // Apply defaults with i18n support
   title = title || (window.i18n ? window.i18n.t('confirm.defaultTitle') : 'Confirm Action');
@@ -588,9 +839,21 @@ async function performRepair() {
 
 function resetPlayButton() {
   isDownloading = false;
-  if (playBtn) {
-    playBtn.disabled = false;
-    playText.textContent = window.i18n ? window.i18n.t('play.play') : 'PLAY';
+  const btn = homePlayBtn || playBtn;
+  if (btn) {
+    btn.disabled = false;
+    const textEl = btn.querySelector('span');
+    if (textEl) textEl.textContent = window.i18n ? window.i18n.t('play.playButton') : 'PLAY HYTALE';
+  }
+}
+
+function lockPlayButton(text) {
+  isDownloading = true;
+  const btn = homePlayBtn || playBtn;
+  if (btn) {
+    btn.disabled = true;
+    const textEl = btn.querySelector('span');
+    if (textEl) textEl.textContent = text || 'LAUNCHING...';
   }
 }
 
@@ -676,6 +939,142 @@ async function loadCustomJavaPath() {
   }
 }
 
+// ==========================================
+// IDENTITY SWITCHER
+// ==========================================
+
+function escapeHtml(text) {
+  const div = document.createElement('div');
+  div.textContent = text;
+  return div.innerHTML;
+}
+
+async function loadIdentities() {
+  try {
+    if (!window.electronAPI) return;
+
+    const nameEl = document.getElementById('currentIdentityName');
+
+    // Load current username
+    let currentUsername = 'Player';
+    if (window.electronAPI.loadUsername) {
+      const name = await window.electronAPI.loadUsername();
+      if (name) currentUsername = name;
+    }
+    if (nameEl) nameEl.textContent = currentUsername;
+
+    // Load all identities for dropdown
+    const list = document.getElementById('identityList');
+    if (!list || !window.electronAPI.getAllUuidMappings) return;
+
+    const mappings = await window.electronAPI.getAllUuidMappings();
+    renderIdentityList(mappings, currentUsername);
+  } catch (error) {
+    console.error('Failed to load identities:', error);
+  }
+}
+
+async function renderIdentityList(mappings, currentUsername) {
+  const list = document.getElementById('identityList');
+  if (!list) return;
+
+  if (!mappings || mappings.length === 0) {
+    list.innerHTML = '<div class="identity-empty">No identities</div>';
+    return;
+  }
+
+  // Check password status for all identities in parallel
+  const statusChecks = mappings.map(async m => {
+    try {
+      if (m.uuid && window.electronAPI?.checkPasswordStatus) {
+        const s = await window.electronAPI.checkPasswordStatus(m.uuid);
+        return s?.hasPassword || false;
+      }
+    } catch {}
+    return false;
+  });
+  const statuses = await Promise.all(statusChecks);
+
+  list.innerHTML = mappings.map((m, i) => {
+    const safe = escapeHtml(m.username);
+    const isActive = m.username === currentUsername;
+    const hasPassword = statuses[i];
+    const pwBadge = hasPassword
+      ? '<span class="pw-badge locked"><i class="fas fa-lock"></i></span>'
+      : '<span class="pw-badge unlocked"><i class="fas fa-unlock"></i></span>';
+    return `
+    <div class="identity-item ${isActive ? 'active' : ''}"
+         onclick="switchIdentity('${safe.replace(/'/g, "&#39;")}')">
+        <span>${safe}</span>
+        ${pwBadge}
+        ${isActive ? '<i class="fas fa-check" style="margin-left:4px;"></i>' : ''}
+    </div>
+  `;
+  }).join('');
+}
+
+window.toggleIdentityDropdown = () => {
+  const dropdown = document.getElementById('identityDropdown');
+  if (dropdown) {
+    dropdown.classList.toggle('show');
+    // Close profile dropdown
+    const profileDropdown = document.getElementById('profileDropdown');
+    if (profileDropdown) profileDropdown.classList.remove('show');
+  }
+};
+
+window.openIdentityManager = () => {
+  // Close dropdown
+  const dropdown = document.getElementById('identityDropdown');
+  if (dropdown) dropdown.classList.remove('show');
+  // Open UUID modal from settings
+  if (window.openUuidModal) {
+    window.openUuidModal();
+  }
+};
+
+window.switchIdentity = async (username) => {
+  try {
+    if (!window.electronAPI || !window.electronAPI.saveUsername) return;
+
+    const result = await window.electronAPI.saveUsername(username);
+    if (result && result.success === false) {
+      throw new Error(result.error || 'Failed to switch identity');
+    }
+
+    // Refresh identity dropdown
+    await loadIdentities();
+
+    // Close dropdown
+    const dropdown = document.getElementById('identityDropdown');
+    if (dropdown) dropdown.classList.remove('show');
+
+    // Update settings page username field and UUID display
+    const settingsInput = document.getElementById('settingsPlayerName');
+    if (settingsInput) settingsInput.value = username;
+    if (window.loadCurrentUuid) window.loadCurrentUuid();
+
+    // Update password shield icon for new identity
+    if (window.updatePasswordShieldIcon) window.updatePasswordShieldIcon();
+
+  } catch (error) {
+    console.error('Failed to switch identity:', error);
+  }
+};
+
+// Make loadIdentities available globally for settings.js to call
+window.loadIdentities = loadIdentities;
+
+window.toggleProfileDropdown = () => {
+  const dropdown = document.getElementById('profileDropdown');
+  if (dropdown) {
+    dropdown.classList.toggle('show');
+    // Close identity dropdown
+    const identityDropdown = document.getElementById('identityDropdown');
+    if (identityDropdown) identityDropdown.classList.remove('show');
+  }
+};
+
 window.launch = launch;
 window.uninstallGame = uninstallGame;
 window.repairGame = repairGame;

GUI/js/ui.js

@@ -79,12 +79,18 @@ function setupWindowControls() {
   const header = document.querySelector('.header');
 
   const profileSelector = document.querySelector('.profile-selector');
+  const identitySelector = document.querySelector('.identity-selector');
 
   if (profileSelector) {
     profileSelector.style.pointerEvents = 'auto';
     profileSelector.style.zIndex = '10000';
   }
 
+  if (identitySelector) {
+    identitySelector.style.pointerEvents = 'auto';
+    identitySelector.style.zIndex = '10000';
+  }
+
   if (windowControls) {
     windowControls.style.pointerEvents = 'auto';
     windowControls.style.zIndex = '10000';
@@ -98,6 +104,9 @@ function setupWindowControls() {
     if (profileSelector) {
       profileSelector.style.webkitAppRegion = 'no-drag';
     }
+    if (identitySelector) {
+      identitySelector.style.webkitAppRegion = 'no-drag';
+    }
   }
 
   if (window.electronAPI) {
@@ -1109,4 +1118,50 @@ window.openDiscordExternal = function() {
 
 window.toggleMaximize = toggleMaximize;
 
+// Global Escape key handler for closing popups/modals/dropdowns
+document.addEventListener('keydown', (e) => {
+  if (e.key !== 'Escape') return;
+
+  // Custom confirm dialogs handle their own Escape — skip if one is open
+  if (document.querySelector('.custom-confirm-modal')) return;
+
+  // Close modals (highest priority)
+  const profileModal = document.getElementById('profileManagerModal');
+  if (profileModal && profileModal.style.display !== 'none') {
+    if (window.closeProfileManager) window.closeProfileManager();
+    return;
+  }
+
+  const uuidModal = document.getElementById('uuidModal');
+  if (uuidModal && uuidModal.style.display !== 'none') {
+    if (window.closeUuidModal) window.closeUuidModal();
+    return;
+  }
+
+  const discordModal = document.getElementById('discordPopupModal');
+  if (discordModal && discordModal.style.display !== 'none') {
+    discordModal.style.display = 'none';
+    return;
+  }
+
+  const versionModal = document.getElementById('versionSelectModal');
+  if (versionModal && versionModal.style.display !== 'none') {
+    versionModal.style.display = 'none';
+    return;
+  }
+
+  // Close dropdowns (lower priority)
+  const identityDropdown = document.getElementById('identityDropdown');
+  if (identityDropdown && identityDropdown.classList.contains('show')) {
+    identityDropdown.classList.remove('show');
+    return;
+  }
+
+  const profileDropdown = document.getElementById('profileDropdown');
+  if (profileDropdown && profileDropdown.classList.contains('show')) {
+    profileDropdown.classList.remove('show');
+    return;
+  }
+});
+
 document.addEventListener('DOMContentLoaded', setupUI);

GUI/locales/ar-SA.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "اللاعبون:",
-    "manageProfiles": "إدارة الملفات الشخصية",
+    "manageProfiles": "إدارة",
+    "manageIdentities": "إدارة",
+    "identityTooltip": "اسم اللاعب ومعرّف UUID المستخدمان في اللعبة",
+    "configTooltip": "إعدادات اللعبة: المودات، Java والذاكرة",
     "defaultProfile": "الافتراضي"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "سلوك المشغل",
     "closeOnStart": "إغلاق المشغل عند بدء اللعبة",
     "closeOnStartDescription": "إغلاق المشغل تلقائياً بعد تشغيل Hytale",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "تسريع الأجهزة (Hardware Acceleration)",
     "hwAccelDescription": "تفعيل تسريع الأجهزة للمشغل",
     "gameBranch": "فرع اللعبة",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "إدارة UUID",
-    "currentUserUUID": "UUID المستخدم الحالي",
     "allPlayerUUIDs": "جميع معرفات UUID للاعبين",
-    "generateNew": "إنشاء UUID جديد",
+    "addIdentity": "إضافة هوية",
+    "usernamePlaceholder": "اسم المستخدم",
+    "add": "إضافة",
+    "cancel": "إلغاء",
+    "advanced": "متقدم",
     "loadingUUIDs": "جاري تحميل الـ UUIDs...",
     "setCustomUUID": "تعيين UUID مخصص",
     "customPlaceholder": "أدخل UUID مخصص (الصيغة: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "نسخ UUID",
     "regenerateTooltip": "إنشاء UUID جديد"
   },
-  "profiles": {
-    "modalTitle": "إدارة الملفات الشخصية",
-    "newProfilePlaceholder": "اسم الملف الشخصي الجديد",
-    "createProfile": "إنشاء ملف شخصي"
+  "configurations": {
+    "modalTitle": "إدارة التكوينات",
+    "newProfilePlaceholder": "اسم التكوين الجديد",
+    "createProfile": "إنشاء تكوين"
   },
   "discord": {
     "notificationText": "انضم إلى مجتمعنا على ديسكورد!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "تم حفظ إعداد تسريع الأجهزة",
     "hwAccelSaveFailed": "فشل حفظ إعداد تسريع الأجهزة",
     "noUsername": "لم يتم تهيئة اسم مستخدم. يرجى حفظ اسم المستخدم أولاً.",
+    "identityAdded": "تمت إضافة الهوية بنجاح!",
+    "identityAddFailed": "فشل في إضافة الهوية",
     "switchUsernameSuccess": "تم التبديل إلى المستخدم \"{username}\" بنجاح!",
     "switchUsernameFailed": "فشل تبديل اسم المستخدم",
     "playerNameTooLong": "يجب أن يكون اسم اللاعب 16 حرفاً أو أقل"
@@ -247,8 +257,8 @@
     "installing": "جاري التثبيت...",
     "extracting": "جاري الاستخراج...",
     "verifying": "جاري التحقق...",
-    "switchingProfile": "جاري تبديل الملف الشخصي...",
-    "profileSwitched": "تم تبديل الملف الشخصي!",
+    "switchingProfile": "جاري تبديل التكوين...",
+    "profileSwitched": "تم تبديل التكوين!",
     "startingGame": "جاري بدء اللعبة...",
     "launching": "جاري التشغيل...",
     "uninstallingGame": "جاري إلغاء تثبيت اللعبة...",

GUI/locales/de-DE.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Spieler:",
-    "manageProfiles": "Profile verwalten",
+    "manageProfiles": "Verwalten",
+    "manageIdentities": "Verwalten",
+    "identityTooltip": "Dein Spielername und UUID im Spiel",
+    "configTooltip": "Spielkonfiguration: Mods, Java- und Speichereinstellungen",
     "defaultProfile": "Standard"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Launcher-Verhalten",
     "closeOnStart": "Launcher beim Spielstart schließen",
     "closeOnStartDescription": "Schließe den Launcher automatisch, nachdem Hytale gestartet wurde",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Hardware-Beschleunigung",
     "hwAccelDescription": "Hardware-Beschleunigung für den Launcher aktivieren",
     "gameBranch": "Spiel-Branch",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "UUID-Verwaltung",
-    "currentUserUUID": "Aktuelle Benutzer-UUID",
     "allPlayerUUIDs": "Alle Spieler-UUIDs",
-    "generateNew": "Neue UUID generieren",
+    "addIdentity": "Identität hinzufügen",
+    "usernamePlaceholder": "Benutzername",
+    "add": "Hinzufügen",
+    "cancel": "Abbrechen",
+    "advanced": "Erweitert",
     "loadingUUIDs": "UUIDs werden geladen...",
     "setCustomUUID": "Benutzerdefinierte UUID festlegen",
     "customPlaceholder": "Benutzerdefinierte UUID eingeben (Format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "UUID kopieren",
     "regenerateTooltip": "Neue UUID generieren"
   },
-  "profiles": {
-    "modalTitle": "Profile verwalten",
-    "newProfilePlaceholder": "Neuer Profilname",
-    "createProfile": "Profil erstellen"
+  "configurations": {
+    "modalTitle": "Konfigurationen verwalten",
+    "newProfilePlaceholder": "Neuer Konfigurationsname",
+    "createProfile": "Konfiguration erstellen"
   },
   "discord": {
     "notificationText": "Tritt unserer Discord-Community bei!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Hardware-Beschleunigungseinstellung gespeichert",
     "hwAccelSaveFailed": "Hardware-Beschleunigungseinstellung konnte nicht gespeichert werden",
     "noUsername": "Kein Benutzername konfiguriert. Bitte speichere zuerst deinen Benutzernamen.",
+    "identityAdded": "Identität erfolgreich hinzugefügt!",
+    "identityAddFailed": "Fehler beim Hinzufügen der Identität",
     "switchUsernameSuccess": "Erfolgreich zu \"{username}\" gewechselt!",
     "switchUsernameFailed": "Benutzername konnte nicht gewechselt werden",
     "playerNameTooLong": "Spielername darf maximal 16 Zeichen haben"
@@ -247,8 +257,8 @@
     "installing": "Installiere...",
     "extracting": "Entpacke...",
     "verifying": "Überprüfe...",
-    "switchingProfile": "Profil wird gewechselt...",
-    "profileSwitched": "Profil gewechselt!",
+    "switchingProfile": "Konfiguration wird gewechselt...",
+    "profileSwitched": "Konfiguration gewechselt!",
     "startingGame": "Spiel wird gestartet...",
     "launching": "STARTET...",
     "uninstallingGame": "Spiel wird deinstalliert...",

GUI/locales/en.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Players:",
-    "manageProfiles": "Manage Profiles",
+    "manageProfiles": "Manage",
+    "manageIdentities": "Manage",
+    "identityTooltip": "Your player name & UUID used in-game",
+    "configTooltip": "Game config: mods, Java & memory settings",
     "defaultProfile": "Default"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Launcher Behavior",
     "closeOnStart": "Close Launcher on game start",
     "closeOnStartDescription": "Automatically close the launcher after Hytale has launched",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Hardware Acceleration",
     "hwAccelDescription": "Enable hardware acceleration for the launcher",
     "gameBranch": "Game Branch",
@@ -162,21 +167,24 @@
   },
   "uuid": {
     "modalTitle": "UUID Management",
-    "currentUserUUID": "Current User UUID",
     "allPlayerUUIDs": "All Player UUIDs",
-    "generateNew": "Generate New UUID",
+    "addIdentity": "Add Identity",
+    "usernamePlaceholder": "Username",
+    "add": "Add",
+    "cancel": "Cancel",
+    "advanced": "Advanced",
     "loadingUUIDs": "Loading UUIDs...",
-    "setCustomUUID": "Set Custom UUID",
+    "setCustomUUID": "Set Custom UUID for Current User",
     "customPlaceholder": "Enter custom UUID (format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
     "setUUID": "Set UUID",
     "warning": "Warning: Setting a custom UUID will change your current player identity",
     "copyTooltip": "Copy UUID",
     "regenerateTooltip": "Generate New UUID"
   },
-  "profiles": {
-    "modalTitle": "Manage Profiles",
-    "newProfilePlaceholder": "New Profile Name",
-    "createProfile": "Create Profile"
+  "configurations": {
+    "modalTitle": "Manage Configurations",
+    "newProfilePlaceholder": "New Configuration Name",
+    "createProfile": "Create Configuration"
   },
   "discord": {
     "notificationText": "Join our Discord community!",
@@ -230,6 +238,8 @@
     "hwAccelSaved": "Hardware acceleration setting saved",
     "hwAccelSaveFailed": "Failed to save hardware acceleration setting",
     "noUsername": "No username configured. Please save your username first.",
+    "identityAdded": "Identity added successfully!",
+    "identityAddFailed": "Failed to add identity",
     "switchUsernameSuccess": "Switched to \"{username}\" successfully!",
     "switchUsernameFailed": "Failed to switch username",
     "playerNameTooLong": "Player name must be 16 characters or less",
@@ -266,8 +276,8 @@
     "installing": "Installing...",
     "extracting": "Extracting...",
     "verifying": "Verifying...",
-    "switchingProfile": "Switching profile...",
-    "profileSwitched": "Profile switched!",
+    "switchingProfile": "Switching configuration...",
+    "profileSwitched": "Configuration switched!",
     "startingGame": "Starting game...",
     "launching": "LAUNCHING...",
     "uninstallingGame": "Uninstalling game...",

GUI/locales/es-ES.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Jugadores:",
-    "manageProfiles": "Gestionar Perfiles",
+    "manageProfiles": "Gestionar",
+    "manageIdentities": "Gestionar",
+    "identityTooltip": "Tu nombre de jugador y UUID usados en el juego",
+    "configTooltip": "Configuración del juego: mods, Java y memoria",
     "defaultProfile": "Predeterminado"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Comportamiento del Launcher",
     "closeOnStart": "Cerrar Launcher al iniciar el juego",
     "closeOnStartDescription": "Cierra automáticamente el launcher después de que Hytale se haya iniciado",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Aceleración por Hardware",
     "hwAccelDescription": "Habilitar aceleración por hardware para el launcher",
     "gameBranch": "Rama del Juego",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "Gestión de UUID",
-    "currentUserUUID": "UUID del usuario actual",
     "allPlayerUUIDs": "Todos los UUIDs de jugadores",
-    "generateNew": "Generar nuevo UUID",
+    "addIdentity": "Añadir identidad",
+    "usernamePlaceholder": "Nombre de usuario",
+    "add": "Añadir",
+    "cancel": "Cancelar",
+    "advanced": "Avanzado",
     "loadingUUIDs": "Cargando UUIDs...",
     "setCustomUUID": "Establecer UUID personalizado",
     "customPlaceholder": "Ingresa un UUID personalizado (formato: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Copiar UUID",
     "regenerateTooltip": "Generar nuevo UUID"
   },
-  "profiles": {
-    "modalTitle": "Gestionar perfiles",
-    "newProfilePlaceholder": "Nombre del nuevo perfil",
-    "createProfile": "Crear perfil"
+  "configurations": {
+    "modalTitle": "Gestionar Configuraciones",
+    "newProfilePlaceholder": "Nombre de la nueva configuración",
+    "createProfile": "Crear Configuración"
   },
   "discord": {
     "notificationText": "¡Únete a nuestra comunidad de Discord!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Configuración de aceleración por hardware guardada",
     "hwAccelSaveFailed": "Error al guardar la configuración de aceleración por hardware",
     "noUsername": "No hay nombre de usuario configurado. Por favor, guarda tu nombre de usuario primero.",
+    "identityAdded": "¡Identidad añadida con éxito!",
+    "identityAddFailed": "Error al añadir identidad",
     "switchUsernameSuccess": "¡Cambiado a \"{username}\" con éxito!",
     "switchUsernameFailed": "Error al cambiar nombre de usuario",
     "playerNameTooLong": "El nombre del jugador debe tener 16 caracteres o menos"
@@ -247,8 +257,8 @@
     "installing": "Instalando...",
     "extracting": "Extrayendo...",
     "verifying": "Verificando...",
-    "switchingProfile": "Cambiando perfil...",
-    "profileSwitched": "¡Perfil cambiado!",
+    "switchingProfile": "Cambiando configuración...",
+    "profileSwitched": "¡Configuración cambiada!",
     "startingGame": "Iniciando juego...",
     "launching": "INICIANDO...",
     "uninstallingGame": "Desinstalando juego...",

GUI/locales/fr-FR.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Joueurs:",
-    "manageProfiles": "Gérer les Profils",
+    "manageProfiles": "Gérer",
+    "manageIdentities": "Gérer",
+    "identityTooltip": "Votre nom de joueur et UUID utilisés en jeu",
+    "configTooltip": "Configuration du jeu : mods, Java et mémoire",
     "defaultProfile": "Par défaut"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Comportement du Launcher",
     "closeOnStart": "Fermer le Launcher au démarrage du jeu",
     "closeOnStartDescription": "Fermer automatiquement le launcher après le lancement d'Hytale",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Accélération Matérielle",
     "hwAccelDescription": "Activer l'accélération matérielle pour le launcher",
     "gameBranch": "Branche du Jeu",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "Gestion UUID",
-    "currentUserUUID": "UUID Utilisateur Actuel",
     "allPlayerUUIDs": "Tous les UUIDs Joueurs",
-    "generateNew": "Générer Nouvel UUID",
+    "addIdentity": "Ajouter une identité",
+    "usernamePlaceholder": "Nom d'utilisateur",
+    "add": "Ajouter",
+    "cancel": "Annuler",
+    "advanced": "Avancé",
     "loadingUUIDs": "Chargement des UUIDs...",
     "setCustomUUID": "Définir UUID Personnalisé",
     "customPlaceholder": "Entrez UUID personnalisé (format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Copier UUID",
     "regenerateTooltip": "Générer Nouvel UUID"
   },
-  "profiles": {
-    "modalTitle": "Gérer les Profils",
-    "newProfilePlaceholder": "Nom du Nouveau Profil",
-    "createProfile": "Créer un Profil"
+  "configurations": {
+    "modalTitle": "Gérer les Configurations",
+    "newProfilePlaceholder": "Nom de la Nouvelle Configuration",
+    "createProfile": "Créer une Configuration"
   },
   "discord": {
     "notificationText": "Rejoignez notre communauté Discord!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Paramètre d'accélération matérielle sauvegardé",
     "hwAccelSaveFailed": "Échec de la sauvegarde du paramètre d'accélération matérielle",
     "noUsername": "Aucun nom d'utilisateur configuré. Veuillez d'abord enregistrer votre nom d'utilisateur.",
+    "identityAdded": "Identité ajoutée avec succès !",
+    "identityAddFailed": "Échec de l'ajout de l'identité",
     "switchUsernameSuccess": "Basculé vers \"{username}\" avec succès!",
     "switchUsernameFailed": "Échec du changement de nom d'utilisateur",
     "playerNameTooLong": "Le nom du joueur doit comporter 16 caractères ou moins"
@@ -247,8 +257,8 @@
     "installing": "Installation...",
     "extracting": "Extraction...",
     "verifying": "Vérification...",
-    "switchingProfile": "Changement de profil...",
-    "profileSwitched": "Profil changé!",
+    "switchingProfile": "Changement de configuration...",
+    "profileSwitched": "Configuration changée !",
     "startingGame": "Démarrage du jeu...",
     "launching": "LANCEMENT...",
     "uninstallingGame": "Désinstallation du jeu...",

GUI/locales/id-ID.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Pemain:",
-    "manageProfiles": "Kelola Profil",
+    "manageProfiles": "Kelola",
+    "manageIdentities": "Kelola",
+    "identityTooltip": "Nama pemain & UUID yang digunakan dalam game",
+    "configTooltip": "Konfigurasi game: mod, Java & pengaturan memori",
     "defaultProfile": "Default"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Perilaku Launcher",
     "closeOnStart": "Tutup launcher saat game dimulai",
     "closeOnStartDescription": "Tutup launcher secara otomatis setelah Hytale diluncurkan",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Akselerasi Perangkat Keras",
     "hwAccelDescription": "Aktifkan akselerasi perangkat keras untuk launcher`",
     "gameBranch": "Cabang Game",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "Manajemen UUID",
-    "currentUserUUID": "UUID Pengguna Saat Ini",
     "allPlayerUUIDs": "Semua UUID Pemain",
-    "generateNew": "Hasilkan UUID Baru",
+    "addIdentity": "Tambah Identitas",
+    "usernamePlaceholder": "Nama Pengguna",
+    "add": "Tambah",
+    "cancel": "Batal",
+    "advanced": "Lanjutan",
     "loadingUUIDs": "Memuat UUID...",
     "setCustomUUID": "Setel UUID Kustom",
     "customPlaceholder": "Masukkan UUID kustom (format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Salin UUID",
     "regenerateTooltip": "Hasilkan UUID Baru"
   },
-  "profiles": {
-    "modalTitle": "Kelola Profil",
-    "newProfilePlaceholder": "Nama Profil Baru",
-    "createProfile": "Buat Profil"
+  "configurations": {
+    "modalTitle": "Kelola Konfigurasi",
+    "newProfilePlaceholder": "Nama Konfigurasi Baru",
+    "createProfile": "Buat Konfigurasi"
   },
   "discord": {
     "notificationText": "Gabung komunitas Discord kami!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Pengaturan akselerasi perangkat keras disimpan",
     "hwAccelSaveFailed": "Gagal menyimpan pengaturan akselerasi perangkat keras",
     "noUsername": "Nama pengguna belum dikonfigurasi. Silakan simpan nama pengguna terlebih dahulu.",
+    "identityAdded": "Identitas berhasil ditambahkan!",
+    "identityAddFailed": "Gagal menambahkan identitas",
     "switchUsernameSuccess": "Berhasil beralih ke \"{username}\"!",
     "switchUsernameFailed": "Gagal beralih nama pengguna",
     "playerNameTooLong": "Nama pemain harus 16 karakter atau kurang"
@@ -247,8 +257,8 @@
     "installing": "Menginstal...",
     "extracting": "Mengekstrak...",
     "verifying": "Memverifikasi...",
-    "switchingProfile": "Beralih profil...",
-    "profileSwitched": "Profil dialihkan!",
+    "switchingProfile": "Beralih konfigurasi...",
+    "profileSwitched": "Konfigurasi dialihkan!",
     "startingGame": "Memulai game...",
     "launching": "MELUNCURKAN...",
     "uninstallingGame": "Menghapus instalasi game...",

GUI/locales/pl-PL.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Graczy:",
-    "manageProfiles": "Zarządzaj Profilami",
+    "manageProfiles": "Zarządzaj",
+    "manageIdentities": "Zarządzaj",
+    "identityTooltip": "Twoja nazwa gracza i UUID używane w grze",
+    "configTooltip": "Konfiguracja gry: mody, Java i ustawienia pamięci",
     "defaultProfile": "Domyślny"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Zachowanie Launchera",
     "closeOnStart": "Zamknij Launcher przy starcie gry",
     "closeOnStartDescription": "Automatycznie zamknij launcher po uruchomieniu Hytale",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Przyspieszenie Sprzętowe",
     "hwAccelDescription": "Włącz przyspieszenie sprzętowe dla launchera",
     "gameBranch": "Gałąź Gry",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "Zarządzanie UUID",
-    "currentUserUUID": "Aktualny UUID użytkownika",
     "allPlayerUUIDs": "Wszystkie identyfikatory UUID graczy",
-    "generateNew": "Wygeneruj nowy UUID",
+    "addIdentity": "Dodaj tożsamość",
+    "usernamePlaceholder": "Nazwa użytkownika",
+    "add": "Dodaj",
+    "cancel": "Anuluj",
+    "advanced": "Zaawansowane",
     "loadingUUIDs": "Ładowanie UUID...",
     "setCustomUUID": "Ustaw niestandardowy UUID",
     "customPlaceholder": "Wprowadź niestandardowy UUID (format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Kopiuj UUID",
     "regenerateTooltip": "Wygeneruj nowy UUID"
   },
-  "profiles": {
-    "modalTitle": "Zarządzaj Profilami",
-    "newProfilePlaceholder": "Nowa Nazwa Profilu",
-    "createProfile": "Utwórz Profil"
+  "configurations": {
+    "modalTitle": "Zarządzaj Konfiguracjami",
+    "newProfilePlaceholder": "Nazwa Nowej Konfiguracji",
+    "createProfile": "Utwórz Konfigurację"
   },
   "discord": {
     "notificationText": "Dołącz do naszej społeczności Discord!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Zapisano ustawienie przyspieszenia sprzętowego",
     "hwAccelSaveFailed": "Nie udało się zapisać ustawienia przyspieszenia sprzętowego",
     "noUsername": "Nie skonfigurowano nazwy użytkownika. Najpierw zapisz swoją nazwę użytkownika.",
+    "identityAdded": "Tożsamość dodana pomyślnie!",
+    "identityAddFailed": "Nie udało się dodać tożsamości",
     "switchUsernameSuccess": "Pomyślnie przełączono na \"{username}\"!",
     "switchUsernameFailed": "Nie udało się przełączyć nazwy użytkownika",
     "playerNameTooLong": "Nazwa gracza musi mieć 16 znaków lub mniej"
@@ -247,8 +257,8 @@
     "installing": "Instalowanie...",
     "extracting": "Ekstraktowanie...",
     "verifying": "Weryfikowanie...",
-    "switchingProfile": "Przełączanie profilu...",
-    "profileSwitched": "Profil zmieniony!",
+    "switchingProfile": "Przełączanie konfiguracji...",
+    "profileSwitched": "Konfiguracja zmieniona!",
     "startingGame": "Uruchamianie gry...",
     "launching": "URUCHAMIANIE...",
     "uninstallingGame": "Odinstalowywanie gry...",

GUI/locales/pt-BR.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Jogadores:",
-    "manageProfiles": "Gerenciar Perfis",
+    "manageProfiles": "Gerenciar",
+    "manageIdentities": "Gerenciar",
+    "identityTooltip": "Seu nome de jogador e UUID usados no jogo",
+    "configTooltip": "Configuração do jogo: mods, Java e memória",
     "defaultProfile": "Padrão"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Comportamento do Lançador",
     "closeOnStart": "Fechar Lançador ao iniciar o jogo",
     "closeOnStartDescription": "Fechar automaticamente o lançador após o Hytale ter sido iniciado",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Aceleração de Hardware",
     "hwAccelDescription": "Ativar aceleração de hardware para o lançador",
     "gameBranch": "Versão do Jogo",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "Gerenciamento de UUID",
-    "currentUserUUID": "UUID do usuário atual",
     "allPlayerUUIDs": "Todos os UUIDs de jogadores",
-    "generateNew": "Gerar novo UUID",
+    "addIdentity": "Adicionar identidade",
+    "usernamePlaceholder": "Nome de usuário",
+    "add": "Adicionar",
+    "cancel": "Cancelar",
+    "advanced": "Avançado",
     "loadingUUIDs": "Carregando UUIDs...",
     "setCustomUUID": "Definir UUID personalizado",
     "customPlaceholder": "Digite um UUID personalizado (formato: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Copiar UUID",
     "regenerateTooltip": "Gerar novo UUID"
   },
-  "profiles": {
-    "modalTitle": "Gerenciar perfis",
-    "newProfilePlaceholder": "Nome do novo perfil",
-    "createProfile": "Criar perfil"
+  "configurations": {
+    "modalTitle": "Gerenciar Configurações",
+    "newProfilePlaceholder": "Nome da Nova Configuração",
+    "createProfile": "Criar Configuração"
   },
   "discord": {
     "notificationText": "Junte-se à nossa comunidade do Discord!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Configuração de aceleração de hardware salva",
     "hwAccelSaveFailed": "Falha ao salvar configuração de aceleração de hardware",
     "noUsername": "Nenhum nome de usuário configurado. Por favor, salve seu nome de usuário primeiro.",
+    "identityAdded": "Identidade adicionada com sucesso!",
+    "identityAddFailed": "Falha ao adicionar identidade",
     "switchUsernameSuccess": "Alterado para \"{username}\" com sucesso!",
     "switchUsernameFailed": "Falha ao trocar nome de usuário",
     "playerNameTooLong": "O nome do jogador deve ter 16 caracteres ou menos"
@@ -247,8 +257,8 @@
     "installing": "Instalando...",
     "extracting": "Extraindo...",
     "verifying": "Verificando...",
-    "switchingProfile": "Alternando perfil...",
-    "profileSwitched": "Perfil alternado!",
+    "switchingProfile": "Alternando configuração...",
+    "profileSwitched": "Configuração alternada!",
     "startingGame": "Iniciando jogo...",
     "launching": "INICIANDO...",
     "uninstallingGame": "Desinstalando jogo...",

GUI/locales/ru-RU.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Игроки:",
-    "manageProfiles": "Управлять профилями:",
+    "manageProfiles": "Управление",
+    "manageIdentities": "Управление",
+    "identityTooltip": "Ваш игровой ник и UUID, используемые в игре",
+    "configTooltip": "Конфигурация игры: моды, Java и настройки памяти",
     "defaultProfile": "По умолчанию"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Поведение лаунчера",
     "closeOnStart": "Закрыть лаунчер при старте игры",
     "closeOnStartDescription": "Автоматически закрыть лаунчер после запуска Hytale",
+    "allowMultiInstance": "Несколько копий игры",
+    "allowMultiInstanceDescription": "Разрешить запуск нескольких клиентов одновременно (полезно для разработки модов)",
     "hwAccel": "Аппаратное ускорение",
     "hwAccelDescription": "Включить аппаратное ускорение для лаунчера",
     "gameBranch": "Ветка игры",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "Управление UUID",
-    "currentUserUUID": "UUID текущего пользователя",
     "allPlayerUUIDs": "UUID всех игроков",
-    "generateNew": "Сгенерировать новый UUID",
+    "addIdentity": "Добавить личность",
+    "usernamePlaceholder": "Имя пользователя",
+    "add": "Добавить",
+    "cancel": "Отмена",
+    "advanced": "Дополнительно",
     "loadingUUIDs": "Загрузка UUID...",
     "setCustomUUID": "Установить кастомный UUID",
     "customPlaceholder": "Ввести кастомный UUID (форматы: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Скопировать UUID",
     "regenerateTooltip": "Сгенерировать новый UUID"
   },
-  "profiles": {
-    "modalTitle": "Управление профилями",
-    "newProfilePlaceholder": "Новое имя профиля",
-    "createProfile": "Создать профиль"
+  "configurations": {
+    "modalTitle": "Управление конфигурациями",
+    "newProfilePlaceholder": "Название новой конфигурации",
+    "createProfile": "Создать конфигурацию"
   },
   "discord": {
     "notificationText": "Присоединитесь к нашему сообществу в Discord!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Настройка аппаратного ускорения сохранена!",
     "hwAccelSaveFailed": "Не удалось сохранить настройку аппаратного ускорения",
     "noUsername": "Имя пользователя не настроено. Пожалуйста, сначала сохраните имя пользователя.",
+    "identityAdded": "Личность успешно добавлена!",
+    "identityAddFailed": "Не удалось добавить личность",
     "switchUsernameSuccess": "Успешно переключено на \"{username}\"!",
     "switchUsernameFailed": "Не удалось переключить имя пользователя",
     "playerNameTooLong": "Имя игрока должно быть не более 16 символов"
@@ -247,8 +257,8 @@
     "installing": "Установка...",
     "extracting": "Извлечение...",
     "verifying": "Проверка...",
-    "switchingProfile": "Смена профиля...",
-    "profileSwitched": "Профиль сменён!",
+    "switchingProfile": "Смена конфигурации...",
+    "profileSwitched": "Конфигурация изменена!",
     "startingGame": "Запуск игры...",
     "launching": "ЗАПУСК...",
     "uninstallingGame": "Удаление игры...",

GUI/locales/sv-SE.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Spelare:",
-    "manageProfiles": "Hantera profiler",
+    "manageProfiles": "Hantera",
+    "manageIdentities": "Hantera",
+    "identityTooltip": "Ditt spelarnamn och UUID som används i spelet",
+    "configTooltip": "Spelkonfiguration: moddar, Java- och minnesinställningar",
     "defaultProfile": "Standard"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Launcher-beteende",
     "closeOnStart": "Stäng launcher vid spelstart",
     "closeOnStartDescription": "Stäng automatiskt launcher efter att Hytale har startats",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Hårdvaruacceleration",
     "hwAccelDescription": "Aktivera hårdvaruacceleration för launchern",
     "gameBranch": "Spelgren",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "UUID-hantering",
-    "currentUserUUID": "Nuvarande användar-UUID",
     "allPlayerUUIDs": "Alla spelare-UUID:er",
-    "generateNew": "Generera ny UUID",
+    "addIdentity": "Lägg till identitet",
+    "usernamePlaceholder": "Användarnamn",
+    "add": "Lägg till",
+    "cancel": "Avbryt",
+    "advanced": "Avancerat",
     "loadingUUIDs": "Laddar UUID:er...",
     "setCustomUUID": "Ange anpassad UUID",
     "customPlaceholder": "Ange anpassad UUID (format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "Kopiera UUID",
     "regenerateTooltip": "Generera ny UUID"
   },
-  "profiles": {
-    "modalTitle": "Hantera profiler",
-    "newProfilePlaceholder": "Nytt profilnamn",
-    "createProfile": "Skapa profil"
+  "configurations": {
+    "modalTitle": "Hantera konfigurationer",
+    "newProfilePlaceholder": "Nytt konfigurationsnamn",
+    "createProfile": "Skapa konfiguration"
   },
   "discord": {
     "notificationText": "Gå med i vår Discord-gemenskap!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Hårdvaruaccelerationsinställning sparad",
     "hwAccelSaveFailed": "Misslyckades med att spara hårdvaruaccelerationsinställning",
     "noUsername": "Inget användarnamn konfigurerat. Vänligen spara ditt användarnamn först.",
+    "identityAdded": "Identitet tillagd!",
+    "identityAddFailed": "Kunde inte lägga till identitet",
     "switchUsernameSuccess": "Bytte till \"{username}\" framgångsrikt!",
     "switchUsernameFailed": "Misslyckades med att byta användarnamn",
     "playerNameTooLong": "Spelarnamnet måste vara 16 tecken eller mindre"
@@ -247,8 +257,8 @@
     "installing": "Installerar...",
     "extracting": "Extraherar...",
     "verifying": "Verifierar...",
-    "switchingProfile": "Byter profil...",
-    "profileSwitched": "Profil bytt!",
+    "switchingProfile": "Byter konfiguration...",
+    "profileSwitched": "Konfiguration bytt!",
     "startingGame": "Startar spel...",
     "launching": "STARTAR...",
     "uninstallingGame": "Avinstallerar spel...",

GUI/locales/tr-TR.json

@@ -8,7 +8,10 @@
   },
   "header": {
     "playersLabel": "Oyuncular:",
-    "manageProfiles": "Profilleri Yönet",
+    "manageProfiles": "Yönet",
+    "manageIdentities": "Yönet",
+    "identityTooltip": "Oyun içinde kullanılan oyuncu adınız ve UUID'niz",
+    "configTooltip": "Oyun yapılandırması: modlar, Java ve bellek ayarları",
     "defaultProfile": "Varsayılan"
   },
   "install": {
@@ -137,6 +140,8 @@
     "closeLauncher": "Başlatıcı Davranışı",
     "closeOnStart": "Oyun başlatıldığında Başlatıcıyı Kapat",
     "closeOnStartDescription": "Hytale başlatıldıktan sonra başlatıcıyı otomatik olarak kapatın",
+    "allowMultiInstance": "Allow multiple game instances",
+    "allowMultiInstanceDescription": "Allow running multiple game clients at the same time (useful for mod development)",
     "hwAccel": "Donanım Hızlandırma",
     "hwAccelDescription": "Başlatıcı için donanım hızlandırmasını etkinleştir",
     "gameBranch": "Oyun Dalı",
@@ -151,9 +156,12 @@
   },
   "uuid": {
     "modalTitle": "UUID Yönetimi",
-    "currentUserUUID": "Geçerli Kullanıcı UUID",
     "allPlayerUUIDs": "Tüm Oyuncu UUID'leri",
-    "generateNew": "Yeni UUID Oluştur",
+    "addIdentity": "Kimlik Ekle",
+    "usernamePlaceholder": "Kullanıcı Adı",
+    "add": "Ekle",
+    "cancel": "İptal",
+    "advanced": "Gelişmiş",
     "loadingUUIDs": "UUID'ler yükleniyor...",
     "setCustomUUID": "Özel UUID Ayarla",
     "customPlaceholder": "Özel UUID girin (format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)",
@@ -162,10 +170,10 @@
     "copyTooltip": "UUID'yi Kopyala",
     "regenerateTooltip": "Yeni UUID Oluştur"
   },
-  "profiles": {
-    "modalTitle": "Profilleri Yönet",
-    "newProfilePlaceholder": "Yeni Profil Adı",
-    "createProfile": "Profil Oluştur"
+  "configurations": {
+    "modalTitle": "Yapılandırmaları Yönet",
+    "newProfilePlaceholder": "Yeni Yapılandırma Adı",
+    "createProfile": "Yapılandırma Oluştur"
   },
   "discord": {
     "notificationText": "Discord topluluğumuza katılın!",
@@ -219,6 +227,8 @@
     "hwAccelSaved": "Donanım hızlandırma ayarı kaydedildi",
     "hwAccelSaveFailed": "Donanım hızlandırma ayarı kaydedilemedi",
     "noUsername": "Kullanıcı adı yapılandırılmadı. Lütfen önce kullanıcı adınızı kaydedin.",
+    "identityAdded": "Kimlik başarıyla eklendi!",
+    "identityAddFailed": "Kimlik eklenemedi",
     "switchUsernameSuccess": "\"{username}\" adına başarıyla geçildi!",
     "switchUsernameFailed": "Kullanıcı adı değiştirilemedi",
     "playerNameTooLong": "Oyuncu adı 16 karakter veya daha az olmalıdır"
@@ -247,8 +257,8 @@
     "installing": "Kuruluyur...",
     "extracting": "Ayıklanıyor...",
     "verifying": "Doğrulanıyor...",
-    "switchingProfile": "Profil değiştiriliyor...",
-    "profileSwitched": "Profil değiştirildi!",
+    "switchingProfile": "Yapılandırma değiştiriliyor...",
+    "profileSwitched": "Yapılandırma değiştirildi!",
     "startingGame": "Oyun başlatılıyor...",
     "launching": "BAŞLATILIYOR...",
     "uninstallingGame": "Oyun kaldırılıyor...",

GUI/style.css

@@ -5575,9 +5575,8 @@ input[type="text"].uuid-input,
     font-family: 'Space Grotesk', sans-serif;
 }
 
-.uuid-current-section,
 .uuid-list-section,
-.uuid-custom-section {
+.uuid-advanced-section {
     background: rgba(255, 255, 255, 0.03);
     border: 1px solid rgba(255, 255, 255, 0.1);
     border-radius: 12px;
@@ -5824,6 +5823,96 @@ input[type="text"].uuid-input,
     color: #3b82f6;
 }
 
+.uuid-item-btn.regenerate:hover {
+    background: rgba(249, 115, 22, 0.2);
+    border-color: rgba(249, 115, 22, 0.4);
+    color: #f97316;
+}
+
+/* Add Identity Form */
+.uuid-add-form {
+    background: rgba(147, 51, 234, 0.05);
+    border: 1px dashed rgba(147, 51, 234, 0.3);
+    border-radius: 8px;
+    padding: 1rem;
+    margin-bottom: 0.75rem;
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+}
+
+.uuid-add-form-row {
+    display: flex;
+    align-items: stretch;
+    gap: 0.5rem;
+}
+
+.uuid-add-form-row .uuid-input {
+    flex: 1;
+    padding: 0.75rem 1rem;
+    border-radius: 8px;
+}
+
+.uuid-add-form-actions {
+    display: flex;
+    gap: 0.5rem;
+    justify-content: flex-end;
+}
+
+.uuid-cancel-btn {
+    padding: 0.75rem 1.25rem;
+    background: rgba(255, 255, 255, 0.05);
+    border: 1px solid rgba(255, 255, 255, 0.2);
+    border-radius: 8px;
+    color: rgba(255, 255, 255, 0.7);
+    font-size: 0.875rem;
+    font-weight: 600;
+    cursor: pointer;
+    transition: all 0.3s ease;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+}
+
+.uuid-cancel-btn:hover {
+    background: rgba(239, 68, 68, 0.15);
+    border-color: rgba(239, 68, 68, 0.3);
+    color: #ef4444;
+}
+
+/* Advanced Section */
+.uuid-advanced-toggle {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    background: none;
+    border: none;
+    color: rgba(255, 255, 255, 0.6);
+    font-size: 0.9rem;
+    font-weight: 600;
+    cursor: pointer;
+    padding: 0.5rem 0;
+    transition: color 0.3s ease;
+    font-family: 'Space Grotesk', sans-serif;
+}
+
+.uuid-advanced-toggle:hover {
+    color: rgba(255, 255, 255, 0.9);
+}
+
+.uuid-advanced-chevron {
+    font-size: 0.75rem;
+    transition: transform 0.3s ease;
+}
+
+.uuid-advanced-chevron.open {
+    transform: rotate(90deg);
+}
+
+.uuid-advanced-content {
+    margin-top: 1rem;
+}
+
 @media (max-width: 600px) {
     .uuid-modal-content {
         width: 95vw;
@@ -5835,8 +5924,8 @@ input[type="text"].uuid-input,
         gap: 1.5rem;
     }
 
-    .uuid-current-display,
-    .uuid-custom-form {
+    .uuid-custom-form,
+    .uuid-add-form-row {
         flex-direction: column;
     }
 
@@ -6213,6 +6302,228 @@ input[type="text"].uuid-input,
     box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
 }
 
+/* Header Tooltip Styles */
+.header-tooltip {
+    position: absolute;
+    top: 100%;
+    left: 50%;
+    transform: translateX(-50%) translateY(4px);
+    font-size: 0.65rem;
+    font-weight: 500;
+    letter-spacing: 0.03em;
+    color: #9ca3af;
+    opacity: 0;
+    transition: opacity 0.2s ease;
+    pointer-events: none;
+    white-space: nowrap;
+    background: rgba(0, 0, 0, 0.85);
+    padding: 0.3rem 0.6rem;
+    border-radius: 6px;
+    border: 1px solid rgba(255, 255, 255, 0.08);
+    z-index: 1;
+}
+
+.identity-selector:hover .header-tooltip,
+.profile-selector:hover .header-tooltip {
+    opacity: 1;
+}
+
+.identity-dropdown.show ~ .header-tooltip,
+.profile-dropdown.show ~ .header-tooltip {
+    opacity: 0 !important;
+}
+
+/* Identity Selector Styles */
+.identity-selector {
+    position: relative;
+    pointer-events: auto;
+    margin-left: 1rem;
+    z-index: 9999 !important;
+}
+
+.identity-btn {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    padding: 0.5rem 1rem;
+    background: rgba(0, 0, 0, 0.4);
+    backdrop-filter: blur(20px);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    border-radius: 12px;
+    color: white;
+    cursor: pointer;
+    font-family: 'Space Grotesk', sans-serif;
+    font-weight: 600;
+    transition: all 0.2s ease;
+    z-index: 100000 !important;
+    pointer-events: auto !important;
+}
+
+.identity-btn:hover {
+    background: rgba(255, 255, 255, 0.1);
+    border-color: rgba(34, 197, 94, 0.4);
+}
+
+.identity-btn i {
+    color: #22c55e;
+}
+
+.identity-btn .password-shield {
+    position: relative;
+    font-size: 0.8rem;
+    padding: 4px 6px;
+    border-radius: 6px;
+    transition: all 0.2s ease;
+    cursor: pointer;
+    z-index: 10;
+}
+
+.identity-btn .password-shield.unprotected {
+    color: #f59e0b;
+    background: rgba(245, 158, 11, 0.15);
+    border: 1px solid rgba(245, 158, 11, 0.3);
+    animation: shieldPulse 2s ease-in-out infinite;
+}
+
+.identity-btn .password-shield.protected {
+    color: #22c55e;
+    background: rgba(34, 197, 94, 0.1);
+    border: 1px solid rgba(34, 197, 94, 0.2);
+    animation: none;
+}
+
+.identity-btn .password-shield:hover {
+    transform: scale(1.15);
+    filter: brightness(1.3);
+}
+
+.identity-btn .password-shield::after {
+    content: attr(data-tooltip);
+    position: absolute;
+    bottom: calc(100% + 8px);
+    left: 50%;
+    transform: translateX(-50%);
+    background: rgba(0, 0, 0, 0.9);
+    color: #fff;
+    padding: 6px 10px;
+    border-radius: 6px;
+    font-size: 0.7rem;
+    font-weight: 400;
+    white-space: nowrap;
+    pointer-events: none;
+    opacity: 0;
+    transition: opacity 0.15s ease;
+    border: 1px solid rgba(255,255,255,0.1);
+}
+
+.identity-btn .password-shield:hover::after {
+    opacity: 1;
+}
+
+@keyframes shieldPulse {
+    0%, 100% { opacity: 1; }
+    50% { opacity: 0.5; }
+}
+
+/* Password status in identity dropdown */
+.identity-item .pw-badge {
+    font-size: 0.65rem;
+    margin-left: auto;
+    padding: 1px 5px;
+    border-radius: 4px;
+}
+.identity-item .pw-badge.locked {
+    color: #22c55e;
+    background: rgba(34, 197, 94, 0.15);
+}
+.identity-item .pw-badge.unlocked {
+    color: #f59e0b;
+    background: rgba(245, 158, 11, 0.1);
+}
+
+.identity-dropdown {
+    position: absolute;
+    top: 100%;
+    left: 0;
+    margin-top: 0.5rem;
+    width: 200px;
+    background: rgba(20, 20, 20, 0.95);
+    backdrop-filter: blur(20px);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    border-radius: 12px;
+    padding: 0.5rem;
+    display: none;
+    flex-direction: column;
+    z-index: 2000;
+    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
+    animation: fadeIn 0.1s ease;
+}
+
+.identity-dropdown.show {
+    display: flex;
+}
+
+.identity-list {
+    max-height: 200px;
+    overflow-y: auto;
+}
+
+.identity-item {
+    padding: 0.6rem 0.8rem;
+    border-radius: 8px;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    color: #ccc;
+    transition: all 0.2s;
+}
+
+.identity-item:hover {
+    background: rgba(255, 255, 255, 0.1);
+    color: white;
+}
+
+.identity-item.active {
+    background: rgba(34, 197, 94, 0.2);
+    color: white;
+    font-weight: bold;
+}
+
+.identity-item.active::before {
+    content: '\2022';
+    color: #22c55e;
+    font-size: 1.2rem;
+}
+
+.identity-divider {
+    height: 1px;
+    background: rgba(255, 255, 255, 0.1);
+    margin: 0.5rem 0;
+}
+
+.identity-action {
+    padding: 0.6rem 0.8rem;
+    border-radius: 8px;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    color: #22c55e;
+    font-weight: 600;
+}
+
+.identity-action:hover {
+    background: rgba(34, 197, 94, 0.1);
+}
+
+.identity-empty {
+    padding: 0.6rem 0.8rem;
+    color: #666;
+    font-size: 0.85rem;
+    text-align: center;
+}
+
 /* Profile Selector Styles */
 .profile-selector {
     position: relative;

backend/core/config.js

@@ -529,7 +529,7 @@ function getAllUuidMappingsArray() {
  * Validates UUID format before saving
  * Preserves original case of username
  */
-function setUuidForUser(username, uuid) {
+function setUuidForUser(username, uuid, { force = false } = {}) {
   const { validate: validateUuid } = require('uuid');
 
   if (!username || typeof username !== 'string' || !username.trim()) {
@@ -543,15 +543,29 @@ function setUuidForUser(username, uuid) {
   const displayName = username.trim();
   const normalizedLookup = displayName.toLowerCase();
 
-  // 1. Update UUID store (source of truth)
+  // 1. Check for existing entries — reject overwrite unless forced
   migrateUuidStoreIfNeeded();
   const uuidStore = loadUuidStore();
   const storeKey = Object.keys(uuidStore).find(k => k.toLowerCase() === normalizedLookup);
+  if (storeKey && uuidStore[storeKey] !== uuid && !force) {
+    console.log(`[Config] Rejected UUID overwrite for "${displayName}": existing ${uuidStore[storeKey]}, attempted ${uuid}`);
+    return { success: false, error: 'duplicate', existingUuid: uuidStore[storeKey] };
+  }
+  // Check if UUID already used by a different name
+  if (!force) {
+    const existingByUuid = Object.entries(uuidStore).find(([k, v]) => v.toLowerCase() === uuid.toLowerCase() && k.toLowerCase() !== normalizedLookup);
+    if (existingByUuid) {
+      console.log(`[Config] Rejected duplicate UUID for "${displayName}": UUID ${uuid} already used by "${existingByUuid[0]}"`);
+      return { success: false, error: 'uuid_in_use', existingUsername: existingByUuid[0] };
+    }
+  }
+
+  // 2. Update UUID store (source of truth)
   if (storeKey) delete uuidStore[storeKey];
   uuidStore[displayName] = uuid;
   saveUuidStore(uuidStore);
 
-  // 2. Update config.json (backward compat)
+  // 3. Update config.json (backward compat)
   const config = loadConfig();
   const userUuids = config.userUuids || {};
   const existingKey = Object.keys(userUuids).find(k => k.toLowerCase() === normalizedLookup);
@@ -560,7 +574,7 @@ function setUuidForUser(username, uuid) {
   saveConfig({ userUuids });
 
   console.log(`[Config] UUID set for "${displayName}": ${uuid}`);
-  return uuid;
+  return { success: true, uuid };
 }
 
 /**
@@ -619,7 +633,7 @@ function resetCurrentUserUuid() {
   const { v4: uuidv4 } = require('uuid');
   const newUuid = uuidv4();
 
-  return setUuidForUser(username, newUuid);
+  return setUuidForUser(username, newUuid, { force: true });
 }
 
 // =============================================================================
@@ -708,6 +722,15 @@ function loadLauncherHardwareAcceleration() {
   return config.launcherHardwareAcceleration !== undefined ? config.launcherHardwareAcceleration : true;
 }
 
+function saveAllowMultiInstance(enabled) {
+  saveConfig({ allowMultiInstance: !!enabled });
+}
+
+function loadAllowMultiInstance() {
+  const config = loadConfig();
+  return config.allowMultiInstance !== undefined ? config.allowMultiInstance : false;
+}
+
 // =============================================================================
 // MODS MANAGEMENT
 // =============================================================================
@@ -1105,6 +1128,8 @@ module.exports = {
   loadCloseLauncherOnStart,
   saveLauncherHardwareAcceleration,
   loadLauncherHardwareAcceleration,
+  saveAllowMultiInstance,
+  loadAllowMultiInstance,
 
   // Mods
   saveModsToConfig,

backend/launcher.js

@@ -20,6 +20,8 @@ const {
 
   saveLauncherHardwareAcceleration,
   loadLauncherHardwareAcceleration,
+  saveAllowMultiInstance,
+  loadAllowMultiInstance,
 
   loadConfig,
   saveConfig,
@@ -151,6 +153,10 @@ module.exports = {
   saveLauncherHardwareAcceleration,
   loadLauncherHardwareAcceleration,
 
+  // Multi-instance functions
+  saveAllowMultiInstance,
+  loadAllowMultiInstance,
+
   // Config functions
   loadConfig,
   saveConfig,

backend/managers/gameLauncher.js

@@ -30,6 +30,7 @@ const { syncModsForCurrentProfile } = require('./modManager');
 const { getUserDataPath } = require('../utils/userDataMigration');
 const { syncServerList } = require('../utils/serverListSync');
 const { killGameProcesses } = require('./gameManager');
+const { loadAllowMultiInstance } = require('../core/config');
 
 // Client patcher for custom auth server (sanasol.ws)
 let clientPatcher = null;
@@ -42,24 +43,51 @@ try {
 const execAsync = promisify(exec);
 
 // Fetch tokens from the auth server (properly signed with server's Ed25519 key)
-async function fetchAuthTokens(uuid, name) {
+async function fetchAuthTokens(uuid, name, password) {
   const authServerUrl = getAuthServerUrl();
   try {
     console.log(`Fetching auth tokens from ${authServerUrl}/game-session/child`);
 
+    const bodyData = {
+      uuid: uuid,
+      name: name,
+      scopes: ['hytale:server', 'hytale:client']
+    };
+    if (password) bodyData.password = password;
+
     const response = await fetch(`${authServerUrl}/game-session/child`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json'
       },
-      body: JSON.stringify({
-        uuid: uuid,
-        name: name,
-        scopes: ['hytale:server', 'hytale:client']
-      })
+      body: JSON.stringify(bodyData)
     });
 
     if (!response.ok) {
+      const errBody = await response.json().catch(() => ({}));
+      if (response.status === 401 && errBody.password_required) {
+        const err = new Error('Password required');
+        err.passwordRequired = true;
+        err.attemptsRemaining = errBody.attemptsRemaining;
+        throw err;
+      }
+      if (response.status === 429) {
+        const err = new Error('Too many failed attempts. Try again later.');
+        err.lockedOut = true;
+        err.lockoutSeconds = errBody.lockoutSeconds;
+        throw err;
+      }
+      if (response.status === 403 && errBody.username_taken) {
+        const err = new Error('This username is reserved by another player who has set a password. Please use a different name.');
+        err.usernameTaken = true;
+        throw err;
+      }
+      if (response.status === 403 && errBody.name_locked) {
+        const err = new Error(`This UUID is locked to username "${errBody.registeredName}". Change your identity name to match.`);
+        err.nameLocked = true;
+        err.registeredName = errBody.registeredName;
+        throw err;
+      }
       throw new Error(`Auth server returned ${response.status}`);
     }
 
@@ -76,10 +104,12 @@ async function fetchAuthTokens(uuid, name) {
         if (payload.username && payload.username !== name && name !== 'Player') {
           console.warn(`[Auth] Token username mismatch: token has "${payload.username}", expected "${name}". Retrying...`);
           // Retry once with explicit name
+          const retryBody = { uuid: uuid, name: name, scopes: ['hytale:server', 'hytale:client'] };
+          if (password) retryBody.password = password;
           const retryResponse = await fetch(`${authServerUrl}/game-session/child`, {
             method: 'POST',
             headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({ uuid: uuid, name: name, scopes: ['hytale:server', 'hytale:client'] })
+            body: JSON.stringify(retryBody)
           });
           if (retryResponse.ok) {
             const retryData = await retryResponse.json();
@@ -98,6 +128,10 @@ async function fetchAuthTokens(uuid, name) {
     console.log('Auth tokens received from server');
     return { identityToken, sessionToken };
   } catch (error) {
+    // Re-throw authentication errors — must not fall back to local tokens
+    if (error.passwordRequired || error.lockedOut || error.usernameTaken || error.nameLocked) {
+      throw error;
+    }
     console.error('Failed to fetch auth tokens:', error.message);
     // Fallback to local generation if server unavailable
     return generateLocalTokens(uuid, name);
@@ -146,7 +180,7 @@ function generateLocalTokens(uuid, name) {
   };
 }
 
-async function launchGame(playerNameOverride = null, progressCallback, javaPathOverride, installPathOverride, gpuPreference = 'auto', branchOverride = null) {
+async function launchGame(playerNameOverride = null, progressCallback, javaPathOverride, installPathOverride, gpuPreference = 'auto', branchOverride = null, options = {}) {
   // ==========================================================================
   // CACHE INVALIDATION: Clear proxyClient module cache to force fresh .env load
   // This prevents stale cached values from affecting multiple launch attempts
@@ -255,11 +289,12 @@ async function launchGame(playerNameOverride = null, progressCallback, javaPathO
   const uuid = getUuidForUser(playerName);
   console.log(`[Launcher] UUID for "${playerName}": ${uuid} (verify this stays constant across launches)`);
 
-  // Fetch tokens from auth server
+  // Fetch tokens from auth server (with password if provided)
   if (progressCallback) {
     progressCallback('Fetching authentication tokens...', null, null, null, null);
   }
-  const { identityToken, sessionToken } = await fetchAuthTokens(uuid, playerName);
+  const launchPassword = options?.password || null;
+  const { identityToken, sessionToken } = await fetchAuthTokens(uuid, playerName, launchPassword);
 
   // Patch client and server binaries to use custom auth server (BEFORE signing on macOS)
   // FORCE patch on every launch to ensure consistency
@@ -464,8 +499,10 @@ async function launchGame(playerNameOverride = null, progressCallback, javaPathO
   }
 
   // Kill any stalled game processes from a previous launch to prevent file locks
-  // and "game already running" issues
-  await killGameProcesses();
+  // and "game already running" issues (skip if multi-instance mode is enabled)
+  if (!loadAllowMultiInstance()) {
+    await killGameProcesses();
+  }
 
   // Remove AOT cache: generated by official Hytale JRE, incompatible with F2P JRE.
   // Client adds -XX:AOTCache when this file exists, causing classloading failures.
@@ -575,7 +612,7 @@ async function launchGame(playerNameOverride = null, progressCallback, javaPathO
   }
 }
 
-async function launchGameWithVersionCheck(playerNameOverride = null, progressCallback, javaPathOverride, installPathOverride, gpuPreference = 'auto', branchOverride = null) {
+async function launchGameWithVersionCheck(playerNameOverride = null, progressCallback, javaPathOverride, installPathOverride, gpuPreference = 'auto', branchOverride = null, options = {}) {
   try {
     // ==========================================================================
     // PRE-LAUNCH VALIDATION: Check username is configured
@@ -648,7 +685,7 @@ async function launchGameWithVersionCheck(playerNameOverride = null, progressCal
       progressCallback('Launching game...', 80, null, null, null);
     }
 
-    const launchResult = await launchGame(playerNameOverride, progressCallback, javaPathOverride, installPathOverride, gpuPreference, branch);
+    const launchResult = await launchGame(playerNameOverride, progressCallback, javaPathOverride, installPathOverride, gpuPreference, branch, options);
     
     // Ensure we always return a result
     if (!launchResult) {
@@ -662,6 +699,10 @@ async function launchGameWithVersionCheck(playerNameOverride = null, progressCal
     if (progressCallback) {
       progressCallback(`Error: ${error.message}`, -1, null, null, null);
     }
+    // Re-throw authentication errors so IPC handler can return proper flags
+    if (error.passwordRequired || error.lockedOut || error.usernameTaken || error.nameLocked) {
+      throw error;
+    }
     // Always return an error response instead of throwing
     return { success: false, error: error.message || 'Unknown launch error' };
   }

backend/managers/javaManager.js

@@ -106,6 +106,23 @@ function getBundledJavaPath(jreDir = JRE_DIR) {
     }
   }
 
+  // Fallback: check for nested JRE directory (e.g. jdk-25.0.2+10-jre/bin/java)
+  // This happens when flattenJREDir fails due to EPERM/EACCES on Windows
+  try {
+    if (fs.existsSync(jreDir)) {
+      const entries = fs.readdirSync(jreDir, { withFileTypes: true });
+      for (const entry of entries) {
+        if (entry.isDirectory() && entry.name !== 'bin' && entry.name !== 'lib') {
+          const nestedCandidate = path.join(jreDir, entry.name, 'bin', JAVA_EXECUTABLE);
+          if (fs.existsSync(nestedCandidate)) {
+            console.log(`[JRE] Using nested Java path: ${nestedCandidate}`);
+            return nestedCandidate;
+          }
+        }
+      }
+    }
+  } catch (_) { /* ignore */ }
+
   return null;
 }
 
@@ -409,7 +426,7 @@ function extractTarGz(tarGzPath, dest) {
 function flattenJREDir(jreLatest) {
   try {
     const entries = fs.readdirSync(jreLatest, { withFileTypes: true });
-    
+
     if (entries.length !== 1 || !entries[0].isDirectory()) {
       return;
     }
@@ -420,12 +437,48 @@ function flattenJREDir(jreLatest) {
     for (const file of files) {
       const oldPath = path.join(nested, file.name);
       const newPath = path.join(jreLatest, file.name);
-      fs.renameSync(oldPath, newPath);
+      try {
+        fs.renameSync(oldPath, newPath);
+      } catch (renameErr) {
+        if (renameErr.code === 'EPERM' || renameErr.code === 'EACCES' || renameErr.code === 'EBUSY') {
+          console.log(`[JRE] Rename failed for ${file.name} (${renameErr.code}), using copy fallback`);
+          copyRecursiveSync(oldPath, newPath);
+        } else {
+          throw renameErr;
+        }
+      }
     }
 
-    fs.rmSync(nested, { recursive: true, force: true });
+    try {
+      fs.rmSync(nested, { recursive: true, force: true });
+    } catch (rmErr) {
+      console.log('[JRE] Could not remove nested JRE dir (non-critical):', rmErr.message);
+    }
   } catch (err) {
-    console.log('Notice: could not restructure Java directory:', err.message);
+    console.error('[JRE] Failed to restructure Java directory:', err.message);
+    // Last resort: check if java exists in a nested subdir and skip flatten
+    try {
+      const entries = fs.readdirSync(jreLatest, { withFileTypes: true });
+      const nestedDir = entries.find(e => e.isDirectory() && e.name !== 'bin' && e.name !== 'lib');
+      if (nestedDir) {
+        const nestedBin = path.join(jreLatest, nestedDir.name, 'bin', process.platform === 'win32' ? 'java.exe' : 'java');
+        if (fs.existsSync(nestedBin)) {
+          console.log(`[JRE] Java found in nested dir: ${nestedDir.name}, leaving structure as-is`);
+        }
+      }
+    } catch (_) { /* ignore */ }
+  }
+}
+
+function copyRecursiveSync(src, dest) {
+  const stat = fs.statSync(src);
+  if (stat.isDirectory()) {
+    fs.mkdirSync(dest, { recursive: true });
+    for (const child of fs.readdirSync(src)) {
+      copyRecursiveSync(path.join(src, child), path.join(dest, child));
+    }
+  } else {
+    fs.copyFileSync(src, dest);
   }
 }
 

docs/FASTUTIL_CLASSLOADER_ISSUE.md

@@ -1,10 +1,10 @@
 # Singleplayer Server Crash: fastutil ClassNotFoundException
 
-## Status: Open (user-specific, Feb 24 2026)
+## Status: Open — NO SOLUTION (Feb 24-27 2026)
 
 ## Symptom
 
-Singleplayer server crashes immediately after DualAuth Agent installs successfully:
+Singleplayer server crashes immediately on boot:
 
 ```
 Exception in thread "main" java.lang.NoClassDefFoundError: it/unimi/dsi/fastutil/objects/ObjectArrayList
@@ -16,98 +16,64 @@ Caused by: java.lang.ClassNotFoundException: it.unimi.dsi.fastutil.objects.Objec
 
 Server exits with code 1. Multiplayer works fine for the same user.
 
-## Affected User
+## Affected Users
+
+1. **ヅ𝚃 JAYED !** (Feb 24) — Windows x86_64, had AOT cache errors before fastutil crash
+2. **Asentrix** (Feb 27) — Windows x86_64 (NT 10.0.26200.0), RTX 4060, Launcher v2.4.4, NO AOT cache errors
 
-- Discord: ヅ𝚃 JAYED !
-- Platform: Windows (standard x86_64, NOT ARM)
 - Reproduces 100% on singleplayer, every attempt
-- Other users (including macOS/Linux) are NOT affected
+- Multiplayer works fine for both users
+- macOS/Linux users are NOT affected
 
-## What Works
+## Ruled Out (confirmed via debug builds)
 
-- Java wrapper correctly strips `-XX:+UseCompactObjectHeaders`
-- Java wrapper correctly injects `--disable-sentry`
-- DualAuth Agent v1.1.12 installs successfully (STATIC mode)
-- Multiplayer connections work fine
-- Repair and reinstall did NOT fix the issue
+| Suspect | Tested | Result |
+|---------|--------|--------|
+| **DualAuth Agent** | Debug build with agent completely disabled (`debug-no-agent` tag) | **Same crash.** Agent is innocent. |
+| **`-Xshare:off` (CDS)** | Added to `JAVA_TOOL_OPTIONS` in launcher code (`debug-xshare-off` tag) | **Did not help.** CDS is not the cause. |
+| **`-XX:+UseCompactObjectHeaders`** | Stripped via wrapper | **Did not help.** Server has `-XX:+IgnoreUnrecognizedVMOptions` anyway. |
+| **Corrupted game files** | User did repair + full reinstall | **Same crash.** |
+| **Java wrapper** | Logs confirm wrapper works correctly | Not the cause. |
+| **ARM64/Parallels** | User is on standard Windows x86_64 | Not applicable. |
+| **AOT cache** | Asentrix has no AOT errors (JAYED did), both crash the same way | Not the root cause. |
 
-## Root Cause Analysis
+## What We Know
 
-`fastutil` (`it.unimi.dsi.fastutil`) should be bundled inside `HytaleServer.jar` (fat JAR). The `ClassNotFoundException` means the JVM's app classloader cannot find it despite it being in the JAR.
+- `fastutil` is bundled inside `HytaleServer.jar` (fat/shaded JAR) — same JAR for all users
+- JVM's `BuiltinClassLoader` cannot find `it.unimi.dsi.fastutil.objects.ObjectArrayList` despite it being in the JAR
+- Crash happens at `EarlyPluginLoader` static initializer (line 34) which imports `ObjectArrayList`
+- The bundled JRE is identical for all users (downloaded by launcher)
+- The issue is **not** caused by anything the F2P launcher adds — it's the vanilla server JVM failing to load its own classes
 
-### Ruled Out
+## Remaining Theories
 
-- **Wrapper issue**: Wrapper is working correctly (confirmed in logs)
-- **UseCompactObjectHeaders**: Server also has `-XX:+IgnoreUnrecognizedVMOptions`, so unrecognized flags don't crash it
-- **DualAuth Agent**: Works for all other users; agent installs successfully before the crash
-- **Corrupted game files**: Repair/reinstall didn't help
-- **ARM64/Parallels**: User is on standard Windows, not ARM
+1. **Antivirus/security software** — Windows Defender or third-party AV intercepting JAR file reads. Real-time scanning + fat JAR = known conflict. **Untested** — user should try disabling AV temporarily.
+2. **Windows Insider build** — Asentrix is on NT 10.0.26200.0 (Windows 11 Dev/Insider). Bleeding-edge Windows may have JVM compatibility issues.
+3. **File locking** — Stalled `java.exe` processes holding `HytaleServer.jar` open (Asentrix had stalled processes killed at every launch).
+4. **Corrupted JRE on disk** — Despite being the same download, filesystem or AV may have corrupted specific JRE files on their system.
 
-### Likely Causes (user-specific)
+## Next Steps to Try
 
-1. **Antivirus interference** — Windows Defender or third-party AV blocking Java from reading classes out of JAR files, especially with `-javaagent` active
-2. **Corrupted/incompatible JRE** — bundled JRE might be broken on their system
-3. **File locking** — another process holding HytaleServer.jar open
+1. **Disable Windows Defender** temporarily — the only quick test left
+2. **Delete bundled JRE** and let launcher re-download — rules out local JRE corruption
+3. **Ask if official Hytale singleplayer works** — if it also crashes, it's their system (but F2P users may not have access)
 
-## Debugging Steps (ask user)
+## Update History
 
-1. **Does official Hytale singleplayer work?** (without F2P launcher)
-   - Yes → something about our launch setup
-   - No → their system/JRE issue
+### Feb 24: First report (JAYED)
+User reported singleplayer crash. Initial investigation found AOT cache errors + fastutil ClassNotFoundException. Stripping `-XX:+UseCompactObjectHeaders` did not help.
 
-2. **Check antivirus** — add game directory to Windows Defender exclusions:
-   - Settings → Windows Security → Virus & threat protection → Exclusions
-   - Add their HytaleF2P install folder
-
-3. **Verify fastutil is in the JAR**:
-   ```cmd
-   jar tf "D:\path\to\Server\HytaleServer.jar" | findstr fastutil
-   ```
-   - If output shows fastutil classes → JAR is fine, classloader issue
-   - If no output → JAR is incomplete/corrupt (different from other users)
-
-4. **Try without DualAuth agent** — rename `dualauth-agent.jar` in Server/ folder, retry singleplayer
-   - If works → agent's classloader manipulation breaks fastutil on their setup
-   - If still fails → unrelated to agent
-
-5. **Check JRE version** — have them run:
-   ```cmd
-   "D:\path\to\jre\latest\bin\java.exe" -version
-   ```
-
-## Update (Feb 24): `-XX:+UseCompactObjectHeaders` stripping removed from defaults
-
-Stripping this flag did NOT fix the issue. The server already has `-XX:+IgnoreUnrecognizedVMOptions` so unrecognized flags are harmless. The flag was removed from default `stripFlags` in `backend/core/config.js`.
-
-## Using the Java Wrapper to Strip JVM Flags
-
-If a user needs to strip a specific JVM flag (e.g., for debugging or compatibility), they can do it via the launcher UI:
-
-1. Open **Settings** → scroll to **Java Wrapper Configuration**
-2. Under **JVM Flags to Remove**, type the flag (e.g. `-XX:+UseCompactObjectHeaders`) and click **Add**
-3. The flag will be stripped from all JVM invocations at launch time
-4. To inject custom arguments, use the **Arguments to Inject** section (with optional "Server Only" condition)
-5. **Restore Defaults** resets to empty strip flags + `--disable-sentry` (server only)
-
-The wrapper generates platform-specific scripts at launch time:
-- **Windows**: `java-wrapper.bat` in `jre/latest/bin/`
-- **macOS/Linux**: `java-wrapper` shell script in the same directory
-
-Config is stored in `config.json` under `javaWrapperConfig`:
-```json
-{
-  "javaWrapperConfig": {
-    "stripFlags": ["-XX:+SomeFlag"],
-    "injectArgs": [
-      { "arg": "--some-arg", "condition": "server" },
-      { "arg": "--other-arg", "condition": "always" }
-    ]
-  }
-}
-```
+### Feb 27: Second report (Asentrix), extensive debugging
+- Asentrix hit same crash, no AOT errors — ruled out AOT as root cause
+- Built `debug-xshare-off`: added `-Xshare:off` to `JAVA_TOOL_OPTIONS` — **did not help**
+- Built `debug-no-agent`: completely disabled DualAuth agent — **same crash**
+- **Conclusion**: Neither the agent nor CDS is the cause. The JVM itself cannot load classes from the fat JAR on these specific Windows systems.
+- Note: wrapper `injectArgs` append AFTER `-jar`, so they cannot inject JVM flags — only `JAVA_TOOL_OPTIONS` works for JVM flags
 
 ## Related
 
 - Java wrapper config: `backend/core/config.js` (stripFlags / injectArgs)
 - DualAuth Agent: v1.1.12, package `ws.sanasol.dualauth`
-- Game version at time of report: `2026.02.19-1a311a592`
+- Game version at time of reports: `2026.02.19-1a311a592`
+- Debug tags: `debug-xshare-off`, `debug-no-agent`
+- Log submission IDs: `c88e7b71` (Asentrix initial), `0445e4dc` (xshare test), `748dceeb` (no-agent test)

main.js

@@ -3,7 +3,7 @@ require('dotenv').config({ path: path.join(__dirname, '.env') });
 const { app, BrowserWindow, ipcMain, dialog, shell } = require('electron');
 const { autoUpdater } = require('electron-updater');
 const fs = require('fs');
-const { launchGame, launchGameWithVersionCheck, installGame, saveUsername, loadUsername, saveJavaPath, loadJavaPath, saveInstallPath, loadInstallPath, saveDiscordRPC, loadDiscordRPC, saveLanguage, loadLanguage, saveCloseLauncherOnStart, loadCloseLauncherOnStart, saveLauncherHardwareAcceleration, loadLauncherHardwareAcceleration, isGameInstalled, uninstallGame, repairGame, getHytaleNews, handleFirstLaunchCheck, proposeGameUpdate, markAsLaunched, loadConfig, saveConfig, checkLaunchReady } = require('./backend/launcher');
+const { launchGame, launchGameWithVersionCheck, installGame, saveUsername, loadUsername, saveJavaPath, loadJavaPath, saveInstallPath, loadInstallPath, saveDiscordRPC, loadDiscordRPC, saveLanguage, loadLanguage, saveCloseLauncherOnStart, loadCloseLauncherOnStart, saveLauncherHardwareAcceleration, loadLauncherHardwareAcceleration, saveAllowMultiInstance, loadAllowMultiInstance, isGameInstalled, uninstallGame, repairGame, getHytaleNews, handleFirstLaunchCheck, proposeGameUpdate, markAsLaunched, loadConfig, saveConfig, checkLaunchReady } = require('./backend/launcher');
 const { retryPWRDownload } = require('./backend/managers/gameManager');
 const { migrateUserDataToCentralized } = require('./backend/utils/userDataMigration');
 
@@ -23,8 +23,9 @@ const profileManager = require('./backend/managers/profileManager');
 
 logger.interceptConsole();
 
-// Single instance lock
-const gotTheLock = app.requestSingleInstanceLock();
+// Single instance lock (skip if multi-instance mode is enabled)
+const multiInstanceEnabled = loadAllowMultiInstance();
+const gotTheLock = multiInstanceEnabled || app.requestSingleInstanceLock();
 
 if (!gotTheLock) {
   console.log('Another instance is already running. Quitting...');
@@ -529,7 +530,26 @@ ipcMain.handle('launch-game', async (event, playerName, javaPath, installPath, g
       }
     };
 
-    const result = await launchGameWithVersionCheck(playerName, progressCallback, javaPath, installPath, gpuPreference);
+    // Check if UUID has password before launching
+    let launchOptions = {};
+    const { getAuthServerUrl, getUuidForUser } = require('./backend/core/config');
+    const launchUuid = getUuidForUser(playerName);
+    try {
+      const uuid = launchUuid;
+      const authServerUrl = getAuthServerUrl();
+      const statusResp = await fetch(`${authServerUrl}/player/password/status/${uuid}`);
+      if (statusResp.ok) {
+        const status = await statusResp.json();
+        if (status.hasPassword) {
+          // Return to renderer to prompt for password
+          return { success: false, passwordRequired: true, uuid };
+        }
+      }
+    } catch (pwErr) {
+      console.log('[Launch] Password check skipped:', pwErr.message);
+    }
+
+    const result = await launchGameWithVersionCheck(playerName, progressCallback, javaPath, installPath, gpuPreference, null, launchOptions);
 
     if (result.success && result.launched) {
       const closeOnStart = loadCloseLauncherOnStart();
@@ -553,10 +573,68 @@ ipcMain.handle('launch-game', async (event, playerName, javaPath, installPath, g
       }, 2000);
     }
 
+    if (error.passwordRequired) {
+      return { success: false, passwordRequired: true, uuid: launchUuid, error: 'Password required' };
+    }
+    if (error.lockedOut) {
+      return { success: false, error: 'Too many failed attempts. Try again in ' + Math.ceil((error.lockoutSeconds || 900) / 60) + ' minutes.' };
+    }
+    if (error.usernameTaken) {
+      return { success: false, usernameTaken: true, error: errorMessage };
+    }
+    if (error.nameLocked) {
+      return { success: false, nameLocked: true, registeredName: error.registeredName, error: error.message };
+    }
+
     return { success: false, error: errorMessage };
   }
 });
 
+ipcMain.handle('launch-game-with-password', async (event, playerName, javaPath, installPath, gpuPreference, password) => {
+  try {
+    const progressCallback = (message, percent, speed, downloaded, total, retryState) => {
+      if (mainWindow && !mainWindow.isDestroyed()) {
+        mainWindow.webContents.send('progress-update', {
+          message: message || null,
+          percent: percent !== null && percent !== undefined ? Math.min(100, Math.max(0, percent)) : null,
+          speed: speed !== null && speed !== undefined ? speed : null,
+          downloaded: downloaded !== null && downloaded !== undefined ? downloaded : null,
+          total: total !== null && total !== undefined ? total : null,
+          retryState: retryState || null
+        });
+      }
+    };
+
+    const result = await launchGameWithVersionCheck(playerName, progressCallback, javaPath, installPath, gpuPreference, null, { password });
+
+    if (result.success && result.launched) {
+      const closeOnStart = loadCloseLauncherOnStart();
+      if (closeOnStart) {
+        setTimeout(() => { app.quit(); }, 1000);
+      }
+    }
+    return result;
+  } catch (error) {
+    console.error('Launch with password error:', error);
+    if (mainWindow && !mainWindow.isDestroyed()) {
+      setTimeout(() => { mainWindow.webContents.send('progress-complete'); }, 2000);
+    }
+    if (error.passwordRequired) {
+      return { success: false, passwordRequired: true, error: 'Incorrect password. ' + (error.attemptsRemaining != null ? error.attemptsRemaining + ' attempts remaining.' : '') };
+    }
+    if (error.lockedOut) {
+      return { success: false, error: 'Too many failed attempts. Try again in ' + Math.ceil((error.lockoutSeconds || 900) / 60) + ' minutes.' };
+    }
+    if (error.usernameTaken) {
+      return { success: false, usernameTaken: true, error: error.message || error.toString() };
+    }
+    if (error.nameLocked) {
+      return { success: false, nameLocked: true, registeredName: error.registeredName, error: error.message };
+    }
+    return { success: false, error: error.message || error.toString() };
+  }
+});
+
 ipcMain.handle('install-game', async (event, playerName, javaPath, installPath, branch) => {
   try {
     console.log(`[IPC] install-game called with parameters:`);
@@ -740,6 +818,15 @@ ipcMain.handle('load-close-launcher', () => {
   return loadCloseLauncherOnStart();
 });
 
+ipcMain.handle('save-allow-multi-instance', (event, enabled) => {
+  saveAllowMultiInstance(enabled);
+  return { success: true };
+});
+
+ipcMain.handle('load-allow-multi-instance', () => {
+  return loadAllowMultiInstance();
+});
+
 ipcMain.handle('save-launcher-hw-accel', (event, enabled) => {
   saveLauncherHardwareAcceleration(enabled);
   return { success: true };
@@ -1342,9 +1429,12 @@ ipcMain.handle('get-all-uuid-mappings', async () => {
   }
 });
 
-ipcMain.handle('set-uuid-for-user', async (event, username, uuid) => {
+ipcMain.handle('set-uuid-for-user', async (event, username, uuid, force) => {
   try {
-    await setUuidForUser(username, uuid);
+    const result = setUuidForUser(username, uuid, { force: !!force });
+    if (result && result.success === false) {
+      return result; // { success: false, error: 'duplicate', existingUuid }
+    }
     return { success: true };
   } catch (error) {
     console.error('Error setting UUID for user:', error);
@@ -1381,6 +1471,88 @@ ipcMain.handle('reset-current-user-uuid', async () => {
   }
 });
 
+// Password Management IPC handlers
+ipcMain.handle('check-password-status', async (event, uuid) => {
+  try {
+    const { getAuthServerUrl } = require('./backend/core/config');
+    const authServerUrl = getAuthServerUrl();
+    const response = await fetch(`${authServerUrl}/player/password/status/${uuid}`);
+    if (!response.ok) return { hasPassword: false };
+    return await response.json();
+  } catch (error) {
+    console.error('Error checking password status:', error);
+    return { hasPassword: false, error: error.message };
+  }
+});
+
+ipcMain.handle('set-player-password', async (event, uuid, password, currentPassword) => {
+  try {
+    const { getAuthServerUrl } = require('./backend/core/config');
+    const { getUuidForUser, loadUsername } = require('./backend/core/config');
+    const authServerUrl = getAuthServerUrl();
+    // First get a bearer token for auth
+    const name = loadUsername() || 'Player';
+    const tokenResp = await fetch(`${authServerUrl}/game-session/child`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ uuid, name, password: currentPassword || undefined })
+    });
+    if (!tokenResp.ok) {
+      const err = await tokenResp.json().catch(() => ({}));
+      return { success: false, error: err.error || 'Failed to authenticate' };
+    }
+    const tokenData = await tokenResp.json();
+    const bearerToken = tokenData.identityToken || tokenData.IdentityToken;
+
+    const response = await fetch(`${authServerUrl}/player/password/set`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        'Authorization': `Bearer ${bearerToken}`
+      },
+      body: JSON.stringify({ uuid, password, currentPassword: currentPassword || undefined })
+    });
+    return await response.json();
+  } catch (error) {
+    console.error('Error setting password:', error);
+    return { success: false, error: error.message };
+  }
+});
+
+ipcMain.handle('remove-player-password', async (event, uuid, currentPassword) => {
+  try {
+    const { getAuthServerUrl } = require('./backend/core/config');
+    const { loadUsername } = require('./backend/core/config');
+    const authServerUrl = getAuthServerUrl();
+    const name = loadUsername() || 'Player';
+    // Get bearer token with current password
+    const tokenResp = await fetch(`${authServerUrl}/game-session/child`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ uuid, name, password: currentPassword })
+    });
+    if (!tokenResp.ok) {
+      const err = await tokenResp.json().catch(() => ({}));
+      return { success: false, error: err.error || 'Failed to authenticate' };
+    }
+    const tokenData = await tokenResp.json();
+    const bearerToken = tokenData.identityToken || tokenData.IdentityToken;
+
+    const response = await fetch(`${authServerUrl}/player/password/remove`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        'Authorization': `Bearer ${bearerToken}`
+      },
+      body: JSON.stringify({ uuid, currentPassword })
+    });
+    return await response.json();
+  } catch (error) {
+    console.error('Error removing password:', error);
+    return { success: false, error: error.message };
+  }
+});
+
 ipcMain.handle('get-recent-logs', async (event, maxLines = 100) => {
   try {
     const logDir = logger.getLogDirectory();

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hytale-f2p-launcher",
-  "version": "2.4.3",
+  "version": "2.4.6",
   "description": "A modern, cross-platform launcher for Hytale with automatic updates and multi-client support",
   "homepage": "https://git.sanhost.net/sanasol/hytale-f2p",
   "main": "main.js",

preload.js

@@ -2,6 +2,7 @@ const { contextBridge, ipcRenderer } = require('electron');
 
 contextBridge.exposeInMainWorld('electronAPI', {
   launchGame: (playerName, javaPath, installPath, gpuPreference) => ipcRenderer.invoke('launch-game', playerName, javaPath, installPath, gpuPreference),
+  launchGameWithPassword: (playerName, javaPath, installPath, gpuPreference, password) => ipcRenderer.invoke('launch-game-with-password', playerName, javaPath, installPath, gpuPreference, password),
   installGame: (playerName, javaPath, installPath, branch) => ipcRenderer.invoke('install-game', playerName, javaPath, installPath, branch),
   closeWindow: () => ipcRenderer.invoke('window-close'),
   minimizeWindow: () => ipcRenderer.invoke('window-minimize'),
@@ -20,6 +21,8 @@ contextBridge.exposeInMainWorld('electronAPI', {
   loadLanguage: () => ipcRenderer.invoke('load-language'),
   saveCloseLauncher: (enabled) => ipcRenderer.invoke('save-close-launcher', enabled),
   loadCloseLauncher: () => ipcRenderer.invoke('load-close-launcher'),
+  saveAllowMultiInstance: (enabled) => ipcRenderer.invoke('save-allow-multi-instance', enabled),
+  loadAllowMultiInstance: () => ipcRenderer.invoke('load-allow-multi-instance'),
   loadConfig: () => ipcRenderer.invoke('load-config'),
   saveConfig: (configUpdate) => ipcRenderer.invoke('save-config', configUpdate),
 
@@ -100,11 +103,20 @@ contextBridge.exposeInMainWorld('electronAPI', {
   // UUID Management methods
   getCurrentUuid: () => ipcRenderer.invoke('get-current-uuid'),
   getAllUuidMappings: () => ipcRenderer.invoke('get-all-uuid-mappings'),
-  setUuidForUser: (username, uuid) => ipcRenderer.invoke('set-uuid-for-user', username, uuid),
+  setUuidForUser: (username, uuid, force) => ipcRenderer.invoke('set-uuid-for-user', username, uuid, force),
   generateNewUuid: () => ipcRenderer.invoke('generate-new-uuid'),
   deleteUuidForUser: (username) => ipcRenderer.invoke('delete-uuid-for-user', username),
   resetCurrentUserUuid: () => ipcRenderer.invoke('reset-current-user-uuid'),
 
+  // Password Management methods
+  checkPasswordStatus: (uuid) => ipcRenderer.invoke('check-password-status', uuid),
+  setPlayerPassword: (uuid, password, currentPassword) => ipcRenderer.invoke('set-player-password', uuid, password, currentPassword),
+  removePlayerPassword: (uuid, currentPassword) => ipcRenderer.invoke('remove-player-password', uuid, currentPassword),
+  promptPassword: () => ipcRenderer.invoke('prompt-password'),
+  onPasswordPrompt: (callback) => {
+    ipcRenderer.on('show-password-prompt', (event, data) => callback(data));
+  },
+
   // Java Wrapper Config API
   loadWrapperConfig: () => ipcRenderer.invoke('load-wrapper-config'),
   saveWrapperConfig: (config) => ipcRenderer.invoke('save-wrapper-config', config),

server/commit-msg.txt

@@ -1,17 +0,0 @@
-## v2.4.0
-
-### New Features
-- **Send Logs** — One-click button to submit launcher & game logs to support. Collects launcher logs, game client logs, and config snapshot into a ZIP, uploads to server, and returns an 8-character ID to share with support ([320ca54](https://git.sanhost.net/sanasol/hytale-f2p/commit/320ca547585c67d0773dba262612db5026378f52), [19c8991](https://git.sanhost.net/sanasol/hytale-f2p/commit/19c8991a44641ebbf44eec73a0ecd9db05241c49))
-- **Arabic (ar-SA) locale** with full RTL support (community contribution by @Yugurten) ([30929ee](https://git.sanhost.net/sanasol/hytale-f2p/commit/30929ee0da5a9c64e65869d6157bd705db3b80f0))
-- **One-click dedicated server scripts** for self-hosting ([552ec42](https://git.sanhost.net/sanasol/hytale-f2p/commit/552ec42d6c7e1e7d1a2803d284019ccae963f41e))
-
-### Bug Fixes
-- Fix Intel Arc iGPU (Meteor Lake/Lunar Lake) on PCI bus 00 being misdetected as discrete GPU on dual-GPU Linux systems ([19c8991](https://git.sanhost.net/sanasol/hytale-f2p/commit/19c8991a44641ebbf44eec73a0ecd9db05241c49))
-- Fix stalled game processes blocking launcher operations — automatic process cleanup on repair and relaunch ([e14d56e](https://git.sanhost.net/sanasol/hytale-f2p/commit/e14d56ef4846423c1fd172d88334cb76193ee741))
-- Fix AOT cache crashes — stale cache cleared before game launch ([e14d56e](https://git.sanhost.net/sanasol/hytale-f2p/commit/e14d56ef4846423c1fd172d88334cb76193ee741))
-- Fix Arabic RTL CSS syntax ([fb90277](https://git.sanhost.net/sanasol/hytale-f2p/commit/fb90277be9cf5f0b8a90195a7d089273b6be082b))
-
-### Other
-- Updated README with Forgejo URLs and server setup video ([a649bf1](https://git.sanhost.net/sanasol/hytale-f2p/commit/a649bf1fcc7cbb2cd0d9aa0160b07828a144b9dd), [66faa1b](https://git.sanhost.net/sanasol/hytale-f2p/commit/66faa1bb1e39575fecb462310af338d13b1cb183))
-
-**Full changelog**: [v2.3.8...v2.4.0](https://git.sanhost.net/sanasol/hytale-f2p/compare/v2.3.8...v2.4.0)