Unreal Engine Issues
Unreal Engine Issues
Assert crash when playing Groom Cache with Card Mesh LOD
UE - Rendering - Features - May 29, 2026Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...
Cannot save actor after actor component modification, Graph is linked to private object(s) in an external package
UE - Gameplay - Blueprint - Sep 28, 2016Cannot save actor after actor component modification. The user gets the error Graph is linked to private object(s) in an external package ...
When having two viewport panes open in editor, and piloting/unpiloting a camera actor in one pane, will cause the other pane to reset viewport camera orientation.
Tools - Jan 8, 2019Piloting and "Un-piloting" a camera Actor in viewport pane causes other viewport panes to reset its view orientation upon "Un-piloting" of Camera Actor. ...
Linked Anim Graph in Post Process Anim BP does NOT work after remove ControlRig Track
zComponent - Archive - Oct 11, 2022After remove control rig track from the skeletal mesh, Linked Anim Graph in Post Process Anim BP of the SK Mesh does NOT work. This issue can be fixed by the following code.// add #include "Anima ...
Editor crash in HairStrandsMeshProjection.cpp when spawning actor with Groom Component bound to skeletal mesh
UE - Gameplay Features - Character - Mar 23, 2026The editor crashes with an assertion failure when placing a Blueprint actor that contains a Groom Component bound to a MetaHuman skeletal mesh. The crash occurs in AddHairStrandInitMeshSamplesPass d ...
Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops
UE - Rendering - Architecture - Niagara - Jul 16, 2025Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...
Animation Constraint Jitter in Sequence when Constraining Layered Control Rig node
UE - ACT Character - Anim in Engine - Nov 6, 2025When using constraints with layered control rigs, you get jitter on the constrained object. ...
Invalid Operand "WorldPartition" when calling FAutomationEditorCommonUtils::CreateNewMap();
UE - Engine Scaling - Streaming - World Partition - May 13, 2022LogAutomationController: Error: LogEditCondition: WorldSettings - EditCondition attempted to use an invalid operand "WorldPartition". ...
UnrealMatch3 ensures when launching on iOS
Docs - Samples - Aug 21, 2016While running regression pass, found that UnrealMatch3 hits an ensure when user selects to Launch on to iOS device. LogOutputDevice:Error: The ini file '../../../UnrealMatch3/Saved/Config/IOS/Device ...
The drawing order of widgets becomes wrong when GlobalInvalidation is enabled,
UE - AI Workflows - UI Systems - Slate - Nov 26, 2021When trying to create a widget with specific steps, the drawing order may not be correct. This is not reproduced when Global Invalidation is disabled, and the state can be restored. This issue is pr ...