This ensure happens only when the Start and End of the sequence is set in the "neigborhood" of the keyframe and only if the project framerate is to be Fixed on 60FPS. If you for example play the whole sequence, setting the Start end End to values 0 and 6000 respectively everything works fine.
Results: When the level sequence reaches frame ~2270 the application throws an error
Expected: There should be no errors
Referenced Ensure
LogOutputDevice: Error: === Handled ensure: === LogOutputDevice: Error: Ensure condition failed: NewTransform.IsValid() [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Engine\Private\Components\SceneComponent.cpp] [Line: 614] LogOutputDevice: Error: Stack: LogOutputDevice: Error: [Callstack] 0x00007ffab0852076 UE4Editor-Engine.dll!USceneComponent::UpdateComponentToWorldWithParent() [d:\build\++ue4\sync\engine\source\runtime\engine\private\components\scenecomponent.cpp:614] LogOutputDevice: Error: [Callstack] 0x00007ffab082d363 UE4Editor-Engine.dll!USceneComponent::InternalSetWorldLocationAndRotation() [d:\build\++ue4\sync\engine\source\runtime\engine\private\components\scenecomponent.cpp:2750] LogOutputDevice: Error: [Callstack] 0x00007ffab082fac1 UE4Editor-Engine.dll!USceneComponent::MoveComponentImpl() [d:\build\++ue4\sync\engine\source\runtime\engine\private\components\scenecomponent.cpp:2873] LogOutputDevice: Error: [Callstack] 0x00007ffab0843635 UE4Editor-Engine.dll!USceneComponent::SetRelativeLocationAndRotation() [d:\build\++ue4\sync\engine\source\runtime\engine\private\components\scenecomponent.cpp:1223] LogOutputDevice: Error: [Callstack] 0x00007ffab084382e UE4Editor-Engine.dll!USceneComponent::SetRelativeLocationAndRotation() [d:\build\++ue4\sync\engine\source\runtime\engine\private\components\scenecomponent.cpp:1241] LogOutputDevice: Error: [Callstack] 0x00007ffaab25f6b6 UE4Editor-MovieSceneTracks.dll!F3DTransformTrackToken::Apply() [d:\build\++ue4\sync\engine\source\runtime\moviescenetracks\private\evaluation\moviescenetemplatecommon.cpp:50] LogOutputDevice: Error: [Callstack] 0x00007ffaab257085 UE4Editor-MovieSceneTracks.dll!FComponentTransformActuator::Actuate() [d:\build\++ue4\sync\engine\source\runtime\moviescenetracks\private\evaluation\moviescene3dtransformtemplate.cpp:90] LogOutputDevice: Error: [Callstack] 0x00007ffaab265c3b UE4Editor-MovieSceneTracks.dll!TBlendableTokenStack<F3DTransformTrackToken>::ComputeAndActuate() [d:\build\++ue4\sync\engine\source\runtime\moviescene\public\evaluation\blending\moviesceneblendingaccumulator.inl:28] LogOutputDevice: Error: [Callstack] 0x00007ffaab429cab UE4Editor-MovieScene.dll!FMovieSceneBlendingAccumulator::Apply() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\evaluation\blending\moviesceneblendingaccumulator.cpp:28] LogOutputDevice: Error: [Callstack] 0x00007ffaab42acf7 UE4Editor-MovieScene.dll!FMovieSceneExecutionTokens::Apply() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\evaluation\moviesceneexecutiontokens.cpp:78] LogOutputDevice: Error: [Callstack] 0x00007ffaab444ba9 UE4Editor-MovieScene.dll!FMovieSceneRootEvaluationTemplateInstance::EvaluateGroup() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\evaluation\moviesceneevaluationtemplateinstance.cpp:347] LogOutputDevice: Error: [Callstack] 0x00007ffaab441cf7 UE4Editor-MovieScene.dll!FMovieSceneRootEvaluationTemplateInstance::Evaluate() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\evaluation\moviesceneevaluationtemplateinstance.cpp:259] LogOutputDevice: Error: [Callstack] 0x00007ffaab495662 UE4Editor-MovieScene.dll!UMovieSceneSequencePlayer::UpdateMovieSceneInstance() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\moviescenesequenceplayer.cpp:683] LogOutputDevice: Error: [Callstack] 0x00007ffaab4962c3 UE4Editor-MovieScene.dll!UMovieSceneSequencePlayer::UpdateTimeCursorPosition_Internal() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\moviescenesequenceplayer.cpp:660] LogOutputDevice: Error: [Callstack] 0x00007ffaab493c9d UE4Editor-MovieScene.dll!UMovieSceneSequencePlayer::Update() [d:\build\++ue4\sync\engine\source\runtime\moviescene\private\moviescenesequenceplayer.cpp:525] LogOutputDevice: Error: [Callstack] 0x00007ffacf70e58c UE4Editor-LevelSequence.dll!ALevelSequenceActor::Tick() [d:\build\++ue4\sync\engine\source\runtime\levelsequence\private\levelsequenceactor.cpp:107] LogOutputDevice: Error: [Callstack] 0x00007ffab034405f UE4Editor-Engine.dll!AActor::TickActor() [d:\build\++ue4\sync\engine\source\runtime\engine\private\actor.cpp:914] LogOutputDevice: Error: [Callstack] 0x00007ffab02ff123 UE4Editor-Engine.dll!FActorTickFunction::ExecuteTick() [d:\build\++ue4\sync\engine\source\runtime\engine\private\actor.cpp:137] LogOutputDevice: Error: [Callstack] 0x00007ffab15a4a2d UE4Editor-Engine.dll!TGraphTask<FTickFunctionTask>::ExecuteTask() [d:\build\++ue4\sync\engine\source\runtime\core\public\async\taskgraphinterfaces.h:829] LogOutputDevice: Error: [Callstack] 0x00007ffab4d71798 UE4Editor-Core.dll!FNamedTaskThread::ProcessTasksNamedThread() [d:\build\++ue4\sync\engine\source\runtime\core\private\async\taskgraph.cpp:679] LogOutputDevice: Error: [Callstack] 0x00007ffab4d71c56 UE4Editor-Core.dll!FNamedTaskThread::ProcessTasksUntilQuit() [d:\build\++ue4\sync\engine\source\runtime\core\private\async\taskgraph.cpp:575] LogOutputDevice: Error: [Callstack] 0x00007ffab4d85085 UE4Editor-Core.dll!FTaskGraphImplementation::WaitUntilTasksComplete() [d:\build\++ue4\sync\engine\source\runtime\core\private\async\taskgraph.cpp:1444] LogOutputDevice: Error: [Callstack] 0x00007ffab15fbb64 UE4Editor-Engine.dll!FTickTaskSequencer::ReleaseTickGroup() [d:\build\++ue4\sync\engine\source\runtime\engine\private\ticktaskmanager.cpp:556] LogOutputDevice: Error: [Callstack] 0x00007ffab160b9a2 UE4Editor-Engine.dll!FTickTaskManager::RunTickGroup() [d:\build\++ue4\sync\engine\source\runtime\engine\private\ticktaskmanager.cpp:1474] LogOutputDevice: Error: [Callstack] 0x00007ffab0cdb6e4 UE4Editor-Engine.dll!UWorld::RunTickGroup() [d:\build\++ue4\sync\engine\source\runtime\engine\private\leveltick.cpp:783] LogOutputDevice: Error: [Callstack] 0x00007ffab0ce74e2 UE4Editor-Engine.dll!UWorld::Tick() [d:\build\++ue4\sync\engine\source\runtime\engine\private\leveltick.cpp:1460] LogOutputDevice: Error: [Callstack] 0x00007ffaaede2085 UE4Editor-UnrealEd.dll!UEditorEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\editorengine.cpp:1726] LogOutputDevice: Error: [Callstack] 0x00007ffaaf702346 UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:403] LogOutputDevice: Error: [Callstack] 0x00007ff65b826225 UE4Editor.exe!FEngineLoop::Tick() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3699] LogOutputDevice: Error: [Callstack] 0x00007ff65b83596c UE4Editor.exe!GuardedMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launch.cpp:174] LogOutputDevice: Error: [Callstack] 0x00007ff65b8359ea UE4Editor.exe!GuardedMainWrapper() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:145] LogOutputDevice: Error: [Callstack] 0x00007ff65b8448da UE4Editor.exe!WinMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:276] LogOutputDevice: Error: [Callstack] 0x00007ff65b84659a UE4Editor.exe!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283] LogOutputDevice: Error: [Callstack] 0x00007ffb05043574 KERNEL32.DLL!UnknownFunction [] LogOutputDevice: Error: [Callstack] 0x00007ffb0767cb81 ntdll.dll!UnknownFunction []
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-72735 in the post.