Revert debug builds, update fastutil issue docs

Agent and -Xshare:off both ruled out as causes.
Restored normal agent injection. Updated docs with
complete findings — issue remains unsolved.

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

GUI/index.html

@@ -592,6 +592,18 @@
                                                 </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" />

GUI/js/settings.js

@@ -6,6 +6,7 @@ let browseJavaBtn;
 let settingsPlayerName;
 let discordRPCCheck;
 let closeLauncherCheck;
+let allowMultiInstanceCheck;
 let launcherHwAccelCheck;
 let gpuPreferenceRadios;
 let gameBranchRadios;
@@ -171,6 +172,7 @@ function setupSettingsElements() {
   settingsPlayerName = document.getElementById('settingsPlayerName');
   discordRPCCheck = document.getElementById('discordRPCCheck');
   closeLauncherCheck = document.getElementById('closeLauncherCheck');
+  allowMultiInstanceCheck = document.getElementById('allowMultiInstanceCheck');
   launcherHwAccelCheck = document.getElementById('launcherHwAccelCheck');
   gpuPreferenceRadios = document.querySelectorAll('input[name="gpuPreference"]');
   gameBranchRadios = document.querySelectorAll('input[name="gameBranch"]');
@@ -218,6 +220,10 @@ function setupSettingsElements() {
     closeLauncherCheck.addEventListener('change', saveCloseLauncher);
   }
 
+  if (allowMultiInstanceCheck) {
+    allowMultiInstanceCheck.addEventListener('change', saveAllowMultiInstance);
+  }
+
   if (launcherHwAccelCheck) {
     launcherHwAccelCheck.addEventListener('change', saveLauncherHwAccel);
   }
@@ -415,6 +421,30 @@ async function loadCloseLauncher() {
   }
 }
 
+async function saveAllowMultiInstance() {
+  try {
+    if (window.electronAPI && window.electronAPI.saveAllowMultiInstance && allowMultiInstanceCheck) {
+      const enabled = allowMultiInstanceCheck.checked;
+      await window.electronAPI.saveAllowMultiInstance(enabled);
+    }
+  } catch (error) {
+    console.error('Error saving multi-instance setting:', error);
+  }
+}
+
+async function loadAllowMultiInstance() {
+  try {
+    if (window.electronAPI && window.electronAPI.loadAllowMultiInstance) {
+      const enabled = await window.electronAPI.loadAllowMultiInstance();
+      if (allowMultiInstanceCheck) {
+        allowMultiInstanceCheck.checked = enabled;
+      }
+    }
+  } catch (error) {
+    console.error('Error loading multi-instance setting:', error);
+  }
+}
+
 async function saveLauncherHwAccel() {
   try {
     if (window.electronAPI && window.electronAPI.saveLauncherHardwareAcceleration && launcherHwAccelCheck) {
@@ -587,6 +617,7 @@ async function loadAllSettings() {
   await loadCurrentUuid();
   await loadDiscordRPC();
   await loadCloseLauncher();
+  await loadAllowMultiInstance();
   await loadLauncherHwAccel();
   await loadGpuPreference();
   await loadVersionBranch();

GUI/locales/ar-SA.json

@@ -140,6 +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",

GUI/locales/de-DE.json

@@ -140,6 +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",

GUI/locales/en.json

@@ -140,6 +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",

GUI/locales/es-ES.json

@@ -140,6 +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",

GUI/locales/fr-FR.json

@@ -140,6 +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",

GUI/locales/id-ID.json

@@ -140,6 +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",

GUI/locales/pl-PL.json

@@ -140,6 +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",

GUI/locales/pt-BR.json

@@ -140,6 +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",

GUI/locales/ru-RU.json

@@ -140,6 +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",

GUI/locales/sv-SE.json

@@ -140,6 +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",

GUI/locales/tr-TR.json

@@ -140,6 +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",

backend/core/config.js

@@ -708,6 +708,15 @@ 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 +1114,8 @@ 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;
@@ -464,8 +465,10 @@ 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.

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...');
@@ -740,6 +741,15 @@ 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 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hytale-f2p-launcher",
-  "version": "2.4.4",
+  "version": "2.4.5",
   "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

@@ -20,6 +20,8 @@ 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),