Unreal Engine Issues
Unreal Engine Issues
Editor crashes when changing skeletal mesh if another skeletal mesh component is attached when using master pose node
OLD - Anim - Jan 27, 2020The crash only occurs if the additional skeletal mesh component is used with Set Master Pose Component (see ToggleAttach function in the TopDownCharacter BP). It doesn't seem to matter what mesh we' ...
CitySample - Level MassCrowd - interactions with SmartObjects/ContextualAnimScene is broken in 5.5
UE - AI - Apr 9, 2025The 5.5 version of the CitySample project, particularly the MassCrowd scene, was not properly maintained. The previously working functionality of NPCs being able to sit on a bench is now broken. CAS ...
Variant Manager: LevelVariantSets asset corruption after rename or duplicate
UE - Editor - Content Pipeline - Variants - Oct 24, 2025When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...
Vertex Color Information Lost on Editor Restart
Tools - Apr 19, 2018This is a regression. In 4.19 and Main (CL 4008322), vertex color information does not save properly and data is lost when editor is reopened. Creating project from scratch instead of copying over f ...
Regression: FAnimInstanceProxy memory leak when BeginDestroy() called on UAnimInstance before USkeletalMeshComponent
UE - Anim - Runtime - Feb 10, 2025In UE 5.5, the fix applied by CL 36529858 in ue5-main updated USkeletalMeshComponent::ClearAnimScriptInstance() to call AnimScriptInstance::UninitializeAnimation() on the animation instance. This, i ...
Crash when attempting to change the parent of a material instance constant through editor scripting
UE - Rendering - Architecture - Materials - Apr 9, 2025The built-in class "UMaterialEditingLibrary" provides various editor scripting functions related to creating and editing materials and material instances. One of these functions, UMaterialEditingLib ...
Rotating a button in UMG and moving it to the edge of the canvas causing incorrect clipping
UE - Editor - UI Systems - Oct 27, 2014When rotating a button in the UMG blueprints and then moving through the edge of the canvas panel it causing the button to clip as though it was never rotated. Update: This also happens when placi ...
Users project crashes when opening level that loads multiple sub-levels
UE - Foundation - Core - UObject - May 31, 2017Users project crashes when opening level that loads multiple sub-levels. Unable to reproduce this in a clean project so the users project is provided though Epic's box account (link is in the repro ...
[CrashReport] UObjectBaseUtility::IsA | UObjectProperty::SerializeItem
UE - Gameplay - Aug 15, 2017This is a trending crash coming out of the 4.17 release. Update: also occurring in 4.18 User DescriptionsCompiled after Refreshing Blueprint node after changine its namePressed compile after creat ...
Root motion from montages does not get mirrored correctly
UE - Anim - Gameplay - Dec 2, 2022A customer noticed that root motion did not mirror properly when using montages. The issue is that the root motion mirroring code is only called from FAnimSync::TickAssetPlayerInstances . Th ...