IL2CPP - Find a reliable solution for stripped IMGUI assemblies

[ManlyMarco]

In most games compiled to IL2CPP the IMGUI assembly is stripped and unstripping fails to restore all of its functions as of the latest BepInEx nightly builds. It's possible to work around this by patching the IMGUI assembly to re-add the missing members, but there needs to be a more reliable and universal solution to this that's not game-specific.

[sis92]

Is https://github.com/yukieiji/UniverseLib/ an alternative solution?

[ManlyMarco]

DearImgui is the top contender so far. Either way the UI will need a major rewrite so that's why there is no progress on this.

[vapopescu]

Any info on how to patch BepInEx\interop\UnityEngine.IMGUIModule.dll in the mean time?

[ManlyMarco]

https://github.com/IllusionMods/BepisPlugins/tree/master/src/IMGUIModule.Il2Cpp.CoreCLR.Patcher

[MagicPro1994]

[Message: Preloader] BepInEx 6.0.0-be.755 - Fallen Elf Freya (1/15/2026 2:58:27 PM)
[Message: Preloader] Built from commit 3fab71a1914132a1ce3a545caf3192da603f2258
[Info : BepInEx] System platform: Windows 10 64-bit
[Info : BepInEx] Process bitness: 64-bit (x64)
[Info : BepInEx] Running under Unity 2021.3.45f2
[Info : BepInEx] Runtime version: 6.0.7
[Info : BepInEx] Runtime information: .NET 6.0.7
[Info : Preloader] 0 patcher plugins loaded
[Info : Preloader] 0 assemblies discovered
[Message:AssemblyPatcher] Executing 0 patch(es)
[Message: BepInEx] Chainloader initialized
[Warning:Il2CppInterop] Class::Init signatures have been exhausted, using a substitute!
[Info :Il2CppInterop] Registered mono type Il2CppInterop.Runtime.DelegateSupport+Il2CppToMonoDelegateReference in il2cpp domain
[Info : BepInEx] 1 plugin to load
[Info : BepInEx] Loading [Runtime Unity Editor 6.3.0]
[Info :Il2CppInterop] Registered mono type RuntimeUnityEditor.Bepin6.IL2CPP.RuntimeUnityEditorPluginIL2CPP+RuntimeUnityEditorHelper in il2cpp domain
[Info :Il2CppInterop] Registered mono type BepInEx.Unity.IL2CPP.Utils.Collections.Il2CppManagedEnumerator in il2cpp domain
[Info :Runtime Unity Editor] Successfully initialized 15/15 features: ContextMenu, CursorUnlocker, MouseInspect, WireframeFeature, Taskbar, ReplWindow, ProfilerWindow, ObjectViewWindow, Inspector, ClipboardWindow, ChangeHistoryWindow, BreakpointsWindow, ObjectTreeViewer, DnSpyHelper, GizmoDrawer
[Message: BepInEx] Chainloader startup complete
[Error :Il2CppInterop] Exception in IL2CPP-to-Managed trampoline, not passing it to il2cpp: System.MissingMethodException: Method not found: 'Void LayoutedWindow..ctor(WindowFunction, UnityEngine.Rect, UnityEngine.GUIContent, Il2CppInterop.Runtime.InteropTypes.Arrays.Il2CppReferenceArray1<UnityEngine.GUILayoutOption>, UnityEngine.GUIStyle)'. at UnityEngine.GUILayout.DoWindow(Int32 id, Rect screenRect, WindowFunction func, GUIContent content, GUIStyle style, Il2CppReferenceArray1 options)
at UnityEngine.GUILayout.Window(Int32 id, Rect screenRect, WindowFunction func, String text, Il2CppReferenceArray`1 options)
at UnityEngine.GUILayout.Window(Int32 id, Rect screenRect, WindowFunction func, String text, GUILayoutOption[] options)
at RuntimeUnityEditor.Core.Taskbar.RuntimeUnityEditor.Core.IFeature.OnOnGUI() in D:\SVN\RuntimeUnityEditor\RuntimeUnityEditor.Core\Windows\Taskbar.cs:line 62
at RuntimeUnityEditor.Core.RuntimeUnityEditorCore.OnGUI() in D:\SVN\RuntimeUnityEditor\RuntimeUnityEditor.Core\RuntimeUnityEditorCore.cs:line 215
at Trampoline_VoidThisRuntimeUnityEditor.Bepin6.IL2CPP.RuntimeUnityEditorPluginIL2CPP+RuntimeUnityEditorHelperOnGUI(IntPtr , Il2CppMethodInfo* )

How to fix this?