Mutable bake instance overwrite instead increments

UE - Anim - Mutable - Nov 13, 2025

We are using Mutable and right now we can't overwrite already baked SK instances. This occurs when, we have a set variation for a character and we address a feedback on one of the used skeletal mesh ...

Build crash when enabling r.CreateShadersOnLoad=1

UE - Rendering - Architecture - Shaders - Nov 10, 2025

When "r.CreateShadersOnLoad" is enabled, cooking will crash due to failure to create a shader. This occurs on //UE5/Release-5.5, CL: 41545209 and //UE5/Release-5.6, CL: 45232827 ...

5.6 Skeletal Meshes with Disabled Sections Flicker in Ray Tracing Scene

UE - Rendering - Graphics Features - Ray Tracing - Nov 7, 2025

Skeletal meshes with disabled mesh sections will flicker in the Hardware Ray Tracing Scene. Also tested on //UE/Release-5.6, CL:45232827 ...

TSparseArray NatVis visualizer doesn't work for arrays that use TInlineSparseArrayAllocator

UE - Foundation - Cpp Tools - Nov 6, 2025

The NatVis visualizer allows many custom Unreal types to be displayed in a helpful manner inside the Visual Studio watch window. One such type is TSparseArray. Under normal circumstances, visualizin ...

GAS: FActiveGameplayCueContainer::RemoveCue crash while iterating removals when consecutive Cue tags are conditionally added and the conditional effects removed in ascending order

UE - Gameplay - Gameplay Ability System - Nov 4, 2025

When removing gameplay effects by tag, if the tag that is being removed has other tags that are dependent on it in a cyclical way an "array out of bounds ' error can be triggered. ...

[AI] Gaps between Nav Mesh tiles in World Partition map causing movement issues

UE - AI - Navigation - Nov 4, 2025

Navmesh has seams between some tiles that are actual edges rather than previously found "gaps" where it was a debug rendering issue. Pathfinding does fail between these tiles to go straight across. ...

Deadlock in UAnimationSequencerDataModel::Evaluate where FScopeLock Lock(&EvaluationLock) blocks execution indefinitely

UE - Anim - Nov 4, 2025

When both the Sequencer Editor and an Animation Curve Editor are open for the same animation asset, the editor freezes completely upon editing the curve. Analysis indicates that the freeze is caus ...

Uploading of the SBT via copy queue is not guaranteed to be synced with async compute queue but only direct queue in d3d12

UE - Rendering - Graphics Features - Ray Tracing - Oct 28, 2025

When HitLighting is enabled, SBT commit is running on the Graphic Queue, and the pass "LumenSceneLighting->offscreenshadows->LumenDirectLightingHardwareRayTracingRGS" that uses SBT could run on the ...

Variant Manager: LevelVariantSets asset corruption after rename or duplicate

UE - Editor - Content Pipeline - Variants - Oct 24, 2025

When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...

Body Setup of a Static Mesh with Simple Collision will pass validation, but removing it and using only a Complex collision and setting Collision Complexity "Use Complex as Simple" will fail validation: "Bone None requires at least one collision shape".

UE - Simulation - Gameplay - Oct 20, 2025

Context: By default, Unreal Engine creates both simple and complex shapes, then, based on what the user wants (complex query versus simple query), the physics solver will use the corresponding shape ...