Unreal Engine Issues
Unreal Engine Issues
Mac project being rejected from app store over read/write access
UE - Platform - Apple - Jan 20, 2016Game was rejected from the Mac App Store for attempting gain read/write access to directories which weren't permitted. Reporter of issue has proposed a possible fix on his AnswerHub post: These tw ...
[CrashReport] UE4Editor_UnrealEd!FAssetEditorToolkit::GetDefaultTabIcon()
Tools - Nov 2, 2017This is a fairly common crash that occurs in the 4.17 and 4.18 releases. This callstack was originally being tracked under [Link Removed], but that had specific repro steps that were confirmed fixed ...
Unable to override private Blueprint variables in child classes
UE - Gameplay - Blueprint - Jun 16, 2022In UE4, "Private" for Blueprint variables was misnamed: its behavior actually meant "Protected". In other words, it can't be read or written to by external objects, but it can be by derived types. A ...
USkeletalMeshComponent::HandleExistingParallelClothSimulation() calling WaitUntilTaskCompletes can trigger arbitrary task that modifies currently iterated UWorld::ComponentsThatNeedPreEndOfFrameSync
UE - Rendering - Architecture - Feb 23, 2024Context ActorComponents can schedule an end-of-frame update for themselves by calling UWorld::MarkActorComponentForNeededEndOfFrameUpdate. The UWorld will iterate all those actor components once pe ...
Physics Asset primitives are being created with the default Name as None instead of BoneName_PrimitiveType
UE - Editor - Content Pipeline - FBX - Oct 27, 2024When creating Physics Assets, either by automatic creation upon import, creation from skeletal meshes already in the project, or when we press Generate All Bodies (bottom right of a opened Physics A ...
[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]
UE - Rendering - RHI - May 29, 2026#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...
AutoSize triggers ensure on shortened Skel Anim Section moved past anim length
zComponent - Archive - May 26, 2026In Sequencer, calling "Edit > Auto Size" on a UMovieSceneSkeletalAnimationSection triggers the LowerBound > UpperBound ensure in UMovieSceneSection::SetRange (MovieSceneSection.h:333) when the secti ...
Orientation Warping breaks incoming poses where bones are in component space
UE - Characters - Animation - Apr 17, 2025The orientation warping node breaks incoming poses where bones are already in component space. This is because, in EvaluateSkeletalControl_AnyThread, we are repeatedly setting bone transforms direc ...
Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor
UE - World Creation - Worldbuilding Tools - World Partition - Dec 18, 2025Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor. As described in the steps to reproduce, if we keep swapping bIsSpatiallyLoaded state and save a Streaming Level ...
Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine
UE - Runtime - Animation - Jan 22, 2026Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine with a "Cannot replace existing object of a different class" message. The conditions to re ...