While playing, select a transient object in the Scene outliner, and you get the following warning:
[2014.11.20-03.37.50:144][784]LogSelection:Warning: PIE object was selected: "GameSession /Game/Maps/UEDPIE_1_Example_Map.Example_Map:PersistentLevel.GameSession_0"
If you then click the ‘Stop’ button, the editor freezes for a while trying to load some debugging DLL, then crashes.
Visual studio debug console log:
[2014.11.20-03.38.26:785][331]LogReferenceChain: Searching referencers for Example_Map. This may take several minutes.
[2014.11.20-03.38.26:901][331]LogReferenceChain: Generating reference graph ...
[2014.11.20-03.38.26:906][331]LogReferenceChain: Level 0 has 12 nodes ...
[2014.11.20-03.38.26:912][331]LogReferenceChain: Level 1 added 74 nodes ...
[2014.11.20-03.38.26:921][331]LogReferenceChain: Level 2 added 228 nodes ...
[2014.11.20-03.38.26:927][331]LogReferenceChain: Level 3 added 176 nodes ...
[2014.11.20-03.38.26:932][331]LogReferenceChain: Level 4 added 22 nodes ...
[2014.11.20-03.38.26:937][331]LogReferenceChain: Level 5 added 0 nodes ...
[2014.11.20-03.38.26:939][331]LogReferenceChain: Generating reference chains ...
[2014.11.20-03.38.26:939][331]LogReferenceChain:
[2014.11.20-03.38.26:939][331]LogReferenceChain: External Referencers:
[2014.11.20-03.38.26:939][331]LogReferenceChain:
[2014.11.20-03.38.26:940][331]LogReferenceChain: (root) UnrealEdEngine /Engine/Transient.UnrealEdEngine_0->Trans
<freeze editor during these logs for ~15 seconds>
'UE4Editor.exe' (Win32): Loaded 'CENSORED\UnrealEngine\Engine\Binaries\Win64\symsrv.dll'. Symbols loaded.
'UE4Editor.exe' (Win32): Unloaded 'CENSORS\UnrealEngine\Engine\Binaries\Win64\symsrv.dll'
<above two lines repeated 37 times>
[2014.11.20-03.38.31:938][331]LogReferenceChain: TransBuffer /Engine/Transient.TransBuffer_0->UE4Editor-UnrealEd.dll!UTransBuffer::AddReferencedObjects() (0x000007fedff06140) + 0 bytes [CENSORED\unrealengine\engine\source\editor\unrealed\private\editortransaction.cpp:384]
[2014.11.20-03.38.31:940][331]LogReferenceChain: GameSession /Game/Maps/UEDPIE_1_Example_Map.Example_Map:PersistentLevel.GameSession_0->Outer
[2014.11.20-03.38.31:941][331]LogReferenceChain: Level /Game/Maps/UEDPIE_1_Example_Map.Example_Map:PersistentLevel->OwningWorld
[2014.11.20-03.38.31:941][331]LogReferenceChain: (target) World /Game/Maps/UEDPIE_1_Example_Map.Example_Map
[2014.11.20-03.38.31:942][331]LogReferenceChain:
[2014.11.20-03.38.31:942][331]LogReferenceChain: (root) UnrealEdEngine /Engine/Transient.UnrealEdEngine_0->Trans
[2014.11.20-03.38.31:943][331]LogReferenceChain: TransBuffer /Engine/Transient.TransBuffer_0->UE4Editor-UnrealEd.dll!UTransBuffer::AddReferencedObjects() (0x000007fedff06140) + 0 bytes [CENSORED\unrealengine\engine\source\editor\unrealed\private\editortransaction.cpp:384]
[2014.11.20-03.38.31:943][331]LogReferenceChain: Brush /Game/Maps/UEDPIE_1_Example_Map.Example_Map:PersistentLevel.BoxBrush_7->Outer
[2014.11.20-03.38.31:943][331]LogReferenceChain: Level /Game/Maps/UEDPIE_1_Example_Map.Example_Map:PersistentLevel->OwningWorld
[2014.11.20-03.38.31:944][331]LogReferenceChain: (target) World /Game/Maps/UEDPIE_1_Example_Map.Example_Map
Fatal error: [File:CENSORED\UnrealEngine\Engine\Source\Developer\MessageLog\Private\Model\MessageLogListingModel.cpp] [Line: 70]
Critical Error HeroFPP_AnimBlueprint_C /Game/Maps/UEDPIE_1_Example_Map.Example_Map:PersistentLevel.MyCharacter_C_0.CharacterMesh1P.HeroFPP_AnimBlueprint_C_1 Object from PIE level still referenced. Shortest path from root: (Object is not currently rooted)
Callstack:
> UE4Editor-Core.dll!StaticFailDebug(const wchar_t * Error, const char * File, int Line, const wchar_t * Description, bool bIsEnsure) Line 186 C++
UE4Editor-Core.dll!FMsg::Logf__VA(const char * File, int Line, const FName & Category, ELogVerbosity::Type Verbosity, const wchar_t * Fmt, ...) Line 519 C++
UE4Editor-MessageLog.dll!FMessageLogListingModel::AddMessageInternal(const TSharedRef<FTokenizedMessage,0> & NewMessage) Line 70 C++
UE4Editor-MessageLog.dll!FMessageLogListingModel::AddMessages(const TArray<TSharedRef<FTokenizedMessage,0>,FDefaultAllocator> & NewMessages) Line 89 C++
UE4Editor-Core.dll!FMessageLog::~FMessageLog() Line 91 C++
UE4Editor-UnrealEd.dll!UEditorEngine::EndPlayMap() Line 217 C++
UE4Editor-UnrealEd.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 1465 C++
UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 278 C++
UE4Editor.exe!FEngineLoop::Tick() Line 2129 C++
UE4Editor.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 133 C++
UE4Editor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow) Line 190 C++