Unreal Editor crashes during map loading at approximately 96% progress, with an EXCEPTION_ACCESS_VIOLATION error in TMulticastDelegateBase::CompactInvocationList() called from UMassSimulationSubsystem::BeginDestroy(). The crash occurs during garbage collection (Collect Garbage) when loading the default map at editor startup. The issue is intermittent. It is not mitigated by any attempted fixes, including clearing caches.
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff
UnrealEditor_MassSimulation!TMulticastDelegateBase::CompactInvocationList() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\MulticastDelegateBase.h:347]
UnrealEditor_MassSimulation!TMulticastDelegateBase::RemoveDelegateInstance() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\MulticastDelegateBase.h:310]
UnrealEditor_MassSimulation!UMassSimulationSubsystem::BeginDestroy() [D:\build++UE5\Sync\Engine\Plugins\Runtime\MassGameplay\Source\MassSimulation\Private\MassSimulationSubsystem.cpp:60]
UnrealEditor_CoreUObject!UObject::ConditionalBeginDestroy() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\Obj.cpp:1220]
UnrealEditor_CoreUObject!UnhashUnreachableObjects() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:5928]
UnrealEditor_CoreUObject!UE::GC::PostCollectGarbageImpl<1>() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:5547]
UnrealEditor_CoreUObject!UE::GC::FReachabilityAnalysisState::PerformReachabilityAnalysisAndConditionallyPurgeGarbage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:5746]
UnrealEditor_CoreUObject!CollectGarbage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:5986]
UnrealEditor_UnrealEd!UEditorEngine::Cleanse() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorEngine.cpp:2820]
UnrealEditor_UnrealEd!UEditorEngine::EditorDestroyWorld() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:2060]
UnrealEditor_UnrealEd!UEditorEngine::Map_Load() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:2456]
UnrealEditor_UnrealEd!UEditorEngine::HandleMapCommand() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:6213]
UnrealEditor_UnrealEd!UEditorEngine::Exec_Editor() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:5674]
UnrealEditor_Core!FExec::Exec() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Misc\Exec.cpp:18]
UnrealEditor_Engine!UEngine::Exec() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp:5027]
UnrealEditor_UnrealEd!UUnrealEdEngine::Exec() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdSrv.cpp:662]
UnrealEditor_UnrealEd!FEditorFileUtils::LoadMap() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\FileHelpers.cpp:2952]
UnrealEditor_UnrealEd!FEditorFileUtils::LoadDefaultMapAtStartup() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\FileHelpers.cpp:4958]
UnrealEditor_UnrealEd!FUnrealEdMisc::OnInit() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdMisc.cpp:375]
UnrealEditor_UnrealEd!EditorInit() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdGlobals.cpp:137]
UnrealEditor!GuardedMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:166]
UnrealEditor!GuardedMainWrapper() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]
UnrealEditor!LaunchWindowsStartup() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]
UnrealEditor!WinMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:317]
UnrealEditor!__scrt_common_main_seh() [D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll
Plugins Enabled: MassEntity, MassGameplay.
Is the problem known? Where can I write and attach files with logs about it?