We’ve been recently getting a rare crash somewhere in the neighbourhood of slate and UMG animations. We have no stable repro, the crash appears seemingly at random, and we need assistance with pinpointing the cause and fix for this.
The only clue is the callstack:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000036
UE::MovieScene::FEntityManager::MigrateEntity() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneEntityManager.cpp:2204]
UE::MovieScene::FEntityManager::AddComponents() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneEntityManager.cpp:1234]
UE::MovieScene::FEntityLedger::UnlinkEverything() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneEntityLedger.cpp:357]
UE::MovieScene::FSequenceInstance::Finish() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneSequenceInstance.cpp:335]
FMovieSceneEntitySystemRunner::GameThread_UpdateSequenceInstances() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneEntitySystemRunner.cpp:844]
FMovieSceneEntitySystemRunner::FlushNext() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneEntitySystemRunner.cpp:344]
FMovieSceneEntitySystemRunner::FlushOutstanding() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\MovieScene\Private\EntitySystem\MovieSceneEntitySystemRunner.cpp:483]
UUMGSequenceTickManager::TickWidgetAnimations() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\UMG\Private\Animation\UMGSequenceTickManager.cpp:228]
TBaseUObjectMethodDelegateInstance<0,UMovieSceneSequenceTickManager,void __cdecl(float),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:667]
TMulticastDelegate<void __cdecl(float),FDefaultDelegateUserPolicy>::Broadcast() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Core\Public\Delegates\DelegateSignatureImpl.inl:1079]
FSlateApplication::TickAndDrawWidgets() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:1673]
FSlateApplication::Tick() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:1577]
FEngineLoop::Tick() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:6005]
GuardedMain() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Launch\Private\Launch.cpp:188]
GuardedMainWrapper() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]
LaunchWindowsStartup() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]
WinMain() [G:\BuildAgent\work\d1f4f4dd347bf222\depot\main\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:318]
__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll
It might also coincide with turning on Global Invalidation, however - we have no proof or certainity that this is the case.
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