Crash level loading world composer

I use 4.8 git branch with win64.

  1. enable worldcomposer
  2. you load a sublevel in worldcomposer (level list)
  3. you click in the content browser on this sublevel to load it
  4. the engine crashes

the crash doesnt happen if you first unload the sublevel in the level list and then click on the sublevel in the content browser.

Hi Wanderer,

Can you post your crash logs and callstack here so I can take a look? Additionally does this occur in a blank project with no additional content?

  1. I created a blank 4.8 git c++ project, dev editor, win64.
  2. Created two empty levels (A and B) with only the default ground/box.
  3. In MapA i put MapB as a sublevel with the worldcomposer enabled. (MapB was automatic added because of the composer)
  4. Save all stuff and you need to have MapA opened with MapB loaded! You should see both maps in the viewport.
  5. I try to open MapB from the content browser.

It crashes. (it only crashes with composer enabled, if its not enabled it doesnt crash)
I think the problem is that the engine wants to load MapB (as a persistent level), but because of the composer its already loaded as a sublevel inside MapA and this causes the crash.

Call Stack:

>	UE4Editor-UnrealEd.dll!UEditorEngine::CheckForWorldGCLeaks(UWorld * NewWorld, UPackage * WorldPackage) Line 1742	C++
 	UE4Editor-UnrealEd.dll!UEditorEngine::EditorDestroyWorld(FWorldContext & Context, const FText & CleanseText, UWorld * NewWorld) Line 1863	C++
 	UE4Editor-UnrealEd.dll!UEditorEngine::Map_Load(const wchar_t * Str, FOutputDevice & Ar) Line 2213	C++
 	UE4Editor-UnrealEd.dll!UEditorEngine::HandleMapCommand(const wchar_t * Str, FOutputDevice & Ar, UWorld * InWorld) Line 5768	C++
 	UE4Editor-UnrealEd.dll!UEditorEngine::Exec(UWorld * InWorld, const wchar_t * Stream, FOutputDevice & Ar) Line 5262	C++
 	UE4Editor-UnrealEd.dll!UUnrealEdEngine::Exec(UWorld * InWorld, const wchar_t * Stream, FOutputDevice & Ar) Line 742	C++
 	UE4Editor-UnrealEd.dll!FEditorFileUtils::LoadMap(const FString & InFilename, bool LoadAsTemplate, const bool bShowProgress) Line 1987	C++
 	UE4Editor-AssetTools.dll!FAssetTypeActions_World::OpenAssetEditor(const TArray<UObject *,FDefaultAllocator> & InObjects, TSharedPtr<IToolkitHost,0> EditWithinLevelEditor) Line 23	C++
 	UE4Editor-UnrealEd.dll!FAssetEditorManager::OpenEditorForAsset(UObject * Asset, const EToolkitMode::Type ToolkitMode, TSharedPtr<IToolkitHost,0> OpenedFromLevelEditor) Line 303	C++
 	UE4Editor-AssetTools.dll!FAssetTypeActions_Base::AssetsActivated(const TArray<UObject *,FDefaultAllocator> & InObjects, EAssetTypeActivationMethod::Type ActivationType) Line 37	C++
 	UE4Editor-ContentBrowser.dll!SContentBrowser::OnAssetsActivated(const TArray<FAssetData,FDefaultAllocator> & ActivatedAssets, EAssetTypeActivationMethod::Type ActivationMethod) Line 1603	C++
 	UE4Editor-ContentBrowser.dll!TBaseSPMethodDelegateInstance<0,SContentBrowser,0,TTypeWrapper<void> __cdecl(TArray<FAssetData,FDefaultAllocator> const & __ptr64,enum EAssetTypeActivationMethod::Type)>::Execute(const TArray<FAssetData,FDefaultAllocator> & <Params_0>, EAssetTypeActivationMethod::Type <Params_1>) Line 282	C++
 	UE4Editor-ContentBrowser.dll!TBaseSPMethodDelegateInstance<0,SContentBrowser,0,void __cdecl(TArray<FAssetData,FDefaultAllocator> const & __ptr64,enum EAssetTypeActivationMethod::Type)>::ExecuteIfSafe(const TArray<FAssetData,FDefaultAllocator> & <Params_0>, EAssetTypeActivationMethod::Type <Params_1>) Line 388	C++
 	UE4Editor-ContentBrowser.dll!SAssetView::OnListMouseButtonDoubleClick(TSharedPtr<FAssetViewItem,0> AssetItem) Line 3222	C++
 	UE4Editor-ContentBrowser.dll!TBaseSPMethodDelegateInstance<0,SAssetView,0,TTypeWrapper<void> __cdecl(TSharedPtr<FAssetViewItem,0>)>::Execute(TSharedPtr<FAssetViewItem,0> <Params_0>) Line 282	C++
 	UE4Editor-ContentBrowser.dll!TBaseSPMethodDelegateInstance<0,SAssetView,0,void __cdecl(TSharedPtr<FAssetViewItem,0>)>::ExecuteIfSafe(TSharedPtr<FAssetViewItem,0> <Params_0>) Line 388	C++
 	UE4Editor-ContentBrowser.dll!TBaseDelegate<void,TSharedPtr<FAssetViewItem,0> >::ExecuteIfBound(TSharedPtr<FAssetViewItem,0> <Params_0>) Line 519	C++
 	UE4Editor-ContentBrowser.dll!SListView<TSharedPtr<FAssetViewItem,0> >::Private_OnItemDoubleClicked(TSharedPtr<FAssetViewItem,0> TheItem) Line 689	C++
 	UE4Editor-ContentBrowser.dll!STableRow<TSharedPtr<FAssetViewItem,0> >::OnMouseButtonDoubleClick(const FGeometry & InMyGeometry, const FPointerEvent & InMouseEvent) Line 252	C++
 	UE4Editor-Slate.dll!FSlateApplication::ProcessMouseButtonDoubleClickEvent::__l3::<lambda>(const FArrangedWidget & TargetWidget, const FPointerEvent & Event) Line 4100	C++
 	UE4Editor-Slate.dll!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,FReply <lambda>(const FArrangedWidget &, const FPointerEvent &) >(FSlateApplication * ThisApplication, FEventRouter::FBubblePolicy RoutingPolicy, FPointerEvent EventCopy, const FSlateApplication::ProcessMouseButtonDoubleClickEvent::__l3::FReply <lambda>(const FArrangedWidget &, const FPointerEvent &) & Lambda) Line 212	C++
 	UE4Editor-Slate.dll!FSlateApplication::ProcessMouseButtonDoubleClickEvent(const TSharedPtr<FGenericWindow,0> & PlatformWindow, FPointerEvent & InMouseEvent) Line 4101	C++
 	UE4Editor-Slate.dll!FSlateApplication::OnMouseDoubleClick(const TSharedPtr<FGenericWindow,0> & PlatformWindow, const EMouseButtons::Type Button) Line 4081	C++
 	UE4Editor-Core.dll!FWindowsApplication::ProcessDeferredMessage(const FDeferredWindowsMessage & DeferredMessage) Line 1348	C++
 	UE4Editor-Core.dll!FWindowsApplication::DeferMessage(TSharedPtr<FWindowsWindow,0> & NativeWindow, HWND__ * InHWnd, unsigned int InMessage, unsigned __int64 InWParam, __int64 InLParam, int MouseX, int MouseY, unsigned int RawInputFlags) Line 1711	C++
 	UE4Editor-Core.dll!FWindowsApplication::ProcessMessage(HWND__ * hwnd, unsigned int msg, unsigned __int64 wParam, __int64 lParam) Line 706	C++
 	UE4Editor-Core.dll!FWindowsApplication::AppWndProc(HWND__ * hwnd, unsigned int msg, unsigned __int64 wParam, __int64 lParam) Line 628	C++
 	[External Code]	
 	UE4Editor-Core.dll!FWindowsPlatformMisc::PumpMessages(bool bFromMainLoop) Line 792	C++
 	UE4Editor.exe!FEngineLoop::Tick() Line 2319	C++
 	UE4Editor.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 142	C++
 	UE4Editor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow) Line 238	C++
 	[External Code]	


+		*RemainingWorld	(Name=0x00000091f22f14b8 "MapA")	UWorld
+		ErrorString	L"   (Object is not currently rooted)\r\n"	FString
		Fatal	Fatal (1)	ELogVerbosity::Type
+		LogEditorServer	{...}	FLogCategoryLogEditorServer
+		RemainingWorld	0x00000091ef288100 (Name=0x00000091f22f14b8 "MapA")	UWorld *
+		Route	Empty	TMap<UObject *,UProperty *,FDefaultSetAllocator,TDefaultMapKeyFuncs<UObject *,UProperty *,0> >
+		TempFname	0x00007ffe8d28c300 L"../../../../../Eigene Dateien/Documents/Unreal Projects/CrashTest/Content/MapB.umap"	wchar_t[512]
+		this	0x00000091e2902b00 (Name=0x00000091d0da9638 "UnrealEdEngine"_0)	UEditorEngine *

Hi Wanderer,

Thank you for the information. I was able to reproduce this on my end and have entered a bug report, UE-15435 to be assessed by the development staff.