Unreal Engine Issues and Bug Tracker (UE-35576)

Description

When using the Event Track to call an event in the Level Blueprint that stops a LevelSequence and then assigns that LevelSequence from another will result in an Access Violation.

Steps to Reproduce

Create new Third Person C++ project
Run project from Visual Studio as Development Editor
Create two LevelSequences named, "Anim1" and "Anim2"
Open Anim1 and add an Event Track
In middle of Event Track, add Event.
Right click Event and go to Properties, change "Value" to "TestEvent"
Save Anim1 and drag it and Anim2 into the Level.
Set both Anim1 and Anim2 to "Auto Play"
Open Level Blueprint and fill out Blueprint logic from attached screenshot.
Save all files
PIE

RESULT:

Access violation on line 800 of BitArray.h

EXPECTED:

No Access violation

Callstack

Access violation reading location 0xFFFFFFFFFFFFFFFF

>	UE4Editor-MovieScene.dll!TConstSetBitIterator<FDefaultBitArrayAllocator>::FindFirstSetBit() Line 800	C++
 	UE4Editor-MovieScene.dll!FMovieSceneSequenceInstance::UpdatePassSingle(EMovieSceneUpdateData & UpdateData, IMovieScenePlayer & Player) Line 240	C++
 	UE4Editor-MovieScene.dll!FMovieSceneSequenceInstance::Update(EMovieSceneUpdateData & UpdateData, IMovieScenePlayer & Player) Line 184	C++
 	UE4Editor-LevelSequence.dll!ULevelSequencePlayer::UpdateMovieSceneInstance(float CurrentPosition, float PreviousPosition) Line 613	C++
 	UE4Editor-Engine.dll!AActor::TickActor(float DeltaSeconds, ELevelTick TickType, FActorTickFunction & ThisTickFunction) Line 831	C++
 	UE4Editor-Engine.dll!FActorTickFunction::ExecuteTick(float DeltaTime, ELevelTick TickType, ENamedThreads::Type CurrentThread, const TRefCountPtr<FGraphEvent> & MyCompletionGraphEvent) Line 112	C++
 	UE4Editor-Engine.dll!FTickFunctionTask::DoTask(ENamedThreads::Type CurrentThread, const TRefCountPtr<FGraphEvent> & MyCompletionGraphEvent) Line 251	C++
 	UE4Editor-Engine.dll!TGraphTask<FTickFunctionTask>::ExecuteTask(TArray<FBaseGraphTask *,FDefaultAllocator> & NewTasks, ENamedThreads::Type CurrentThread) Line 868	C++
 	UE4Editor-Core.dll!FNamedTaskThread::ProcessTasksNamedThread(int QueueIndex, bool bAllowStall) Line 932	C++
 	UE4Editor-Core.dll!FNamedTaskThread::ProcessTasksUntilQuit(int QueueIndex) Line 679	C++
 	UE4Editor-Core.dll!FTaskGraphImplementation::WaitUntilTasksComplete(const TArray<TRefCountPtr<FGraphEvent>,TInlineAllocator<4,FDefaultAllocator> > & Tasks, ENamedThreads::Type CurrentThreadIfKnown) Line 1776	C++
 	UE4Editor-Engine.dll!FTickTaskSequencer::ReleaseTickGroup(ETickingGroup WorldTickGroup, bool bBlockTillComplete) Line 520	C++
 	UE4Editor-Engine.dll!FTickTaskManager::RunTickGroup(ETickingGroup Group, bool bBlockTillComplete) Line 1426	C++
 	UE4Editor-Engine.dll!UWorld::RunTickGroup(ETickingGroup Group, bool bBlockTillComplete) Line 706	C++
 	UE4Editor-Engine.dll!UWorld::Tick(ELevelTick TickType, float DeltaSeconds) Line 1275	C++
 	UE4Editor-UnrealEd.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 1408	C++
 	UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 371	C++
 	UE4Editor.exe!FEngineLoop::Tick() Line 2834	C++
 	UE4Editor.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 156	C++
 	UE4Editor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow) Line 191	C++
 	[External Code]

Community References

Editor crash when I call Stop + SetSequence from the Event Track

Can't get actor components to replicate from client to server

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Fixed

Component	UE - Anim - Sequencer
Affects Versions	4.13
Target Fix	4.15

Fix Commit	3163859
Main Commit	3178562

Created	Sep 5, 2016
Resolved	Oct 21, 2016
Updated	May 2, 2018

UE-35576

Access violation when calling Stop + SetSequence from Event set in Event Track

Access violation when calling Stop + SetSequence from Event set in Event Track

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