Crash at Skeleton Remapping

UE - Anim - Runtime - Nov 14, 2025

The details are in the EPS : [Link Removed] ...

Typo in NaniteRasterizer.usf preventing low tessellation mode at distance

UE - Graphics Features - Nanite - Nov 12, 2025

A typo in a conditional compilation macro in NaniteRasterizer.usf causes code controlling distant tessellation reduction to never be included in final shader code. This means that the low tessellati ...

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 ...

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. ...

TOptional value changes in parent BP don't propagate to loaded child BPs

UE - Framework - Blueprint Editor - Oct 27, 2025

Context TOptional<T> is a wrapping struct around a type, that lets the property have an set and unset state, in addition to the property's value when set. It is editor exposed: designers can open b ...

Lumen reflections break when the normals don't match the pixel depth information.

UE - Graphics Features - Lumen - Oct 23, 2025

Lumen Reflections can leave black spots in chrome materials with strong normals. Also tested on UE 5.5, CL: 41545209 and UE 5.6, CL: 45232827 ...

World Position Offset invalidates Point Lights Entire Virtual Shadow Map Cache when light frustrum is only overlapping a small portion of the mesh

UE - Graphics Features - Oct 22, 2025

When adding a spotlight to the scene it does not correctly use cached virtual shadow map pages when the spotlight overlaps a mesh using WPO. This can be most easily observed by entering 'Cached Pag ...

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 ...

HZB Occlusion causes large stalls on the render thread

UE - Rendering Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...