Unreal Engine Issues

UE-38285

Crash when destroying a Widget Component during the OnAnimationFinished delegate of it's UserWidget

Crash when destroying a Widget Component during the OnAnimationFinished delegate of it's UserWidget

Developer Notes

This issue has been closed as 'Won't Fix' due to an extended period of time without updates. If this issue is important to you please let us know by posting on the AnswerHub or UDN, and Epic will re-open the ticket for further review.

UDN
Description

UserWidget animations will be ticked as part of the WidgetComponent's DrawWidgetToRenderTarget(). This will lead to a crash when we attempt to set the LastWidgetRenderTime to GetWorld()->TimeSeconds. A null check can prevent this.

Steps to Reproduce
  1. Create a widget with an animation
  2. Create an actor BP that adds a widget component, creates your widget, and sets it to the widget component
  3. Make the actor BP bind an event to OnAnimationFinished and play the animation
  4. In OnAnimationFinished, destroy the widget component
  5. Engine will crash when animation finishes
Callstack
UE4Editor_UMG!TArray<TSharedPtr<FSlateWindowElementList::FDeferredPaint,0>,FDefaultAllocator>::operator=() array.h:743 
UE4Editor_UMG!FWidgetRenderer::DrawWindow() widgetrenderer.cpp:239 
UE4Editor_UMG!FWidgetRenderer::DrawWindow() widgetrenderer.cpp:180 
UE4Editor_UMG!UWidgetComponent::DrawWidgetToRenderTarget() widgetcomponent.cpp:673 
UE4Editor_UMG!UWidgetComponent::TickComponent() widgetcomponent.cpp:552 
UE4Editor_Engine!FActorComponentTickFunction::ExecuteTickHelper<<lambda_aa79ebd94b2c9e6b2d520765e2e11e5e> >() actor.h:2937 
UE4Editor_Engine!FActorComponentTickFunction::ExecuteTick() actorcomponent.cpp:707 
UE4Editor_Engine!FTickFunctionTask::DoTask() ticktaskmanager.cpp:251 
UE4Editor_Engine!TGraphTask<FTickFunctionTask>::ExecuteTask() taskgraphinterfaces.h:868 
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() taskgraph.cpp:932 
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilIdle() taskgraph.cpp:694 
UE4Editor_Engine!FTickTaskSequencer::ReleaseTickGroup() ticktaskmanager.cpp:537 
UE4Editor_Engine!FTickTaskManager::RunTickGroup() ticktaskmanager.cpp:1426 
UE4Editor_Engine!UWorld::RunTickGroup() leveltick.cpp:706 
UE4Editor_Engine!UWorld::Tick() leveltick.cpp:1286 
UE4Editor_UnrealEd!UEditorEngine::Tick() editorengine.cpp:1408 
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() unrealedengine.cpp:371 
UE4Editor!FEngineLoop::Tick() launchengineloop.cpp:2834 
UE4Editor!GuardedMain() launch.cpp:156 
UE4Editor!GuardedMainWrapper() launchwindows.cpp:126 
UE4Editor!WinMain() launchwindows.cpp:202 
UE4Editor!__scrt_common_main_seh() exe_common.inl:253 
kernel32!<Unknown> 
ntdll!<Unknown>

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Won't Fix
ComponentUE - Editor - UI Systems
Affects Versions4.13, 4.15
CreatedNov 4, 2016
ResolvedJun 13, 2017
UpdatedApr 27, 2018
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