RigVMRegistry : The registry is not locked for writing yet : ensure statement error during cook

UE - Anim - Rigging - Control Rig - Sep 2, 2025

I am seeing an cook failure at the very beginning. It goes away with a retry step via Horde. Please find attached call stack. I am able to consistently reproduce it by wiping all the DDC cache and ...

Precision issues with 16-bit Skin Cache shaders.

UE - Rendering Architecture - Sep 2, 2025

A licensee reported precision issues with position in the gpu skin cache shaders with 16-bit real types enabled. ...

When ControlRig.EnableAnimNodePerformanceOptimizations is enabled, the default pose briefly appears after the Control Rig is reinitialized

UE - Anim - Rigging - Control Rig - Sep 1, 2025

Since UE5.6, ControlRig.EnableAnimNodePerformanceOptimizations is enabled by default, and this appears to be causing the issue. Specifically, when the control rig’s construction event is processed, ...

Crash when running "MAP REBUILD ALLVISIBLE" with hidden sublevels and then changing maps

UE - World Creation - Worldbuilding Tools - Sep 1, 2025

Running the MAP REBUILD ALLVISIBLE editor command when the current map contains hidden sublevels causes a crash upon changing maps. The issue seems to be related to hidden sublevels being cleared in ...

Material Particle SubUV Sample does not work with Tex Object

UE - Rendering Architecture - Materials - Aug 29, 2025

The Particle SubUV Sample node uses its own texture object reference instead of the one provided by the texture object node. ...

Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization

UE - Rendering Architecture - Shaders - Aug 27, 2025

In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...

GAS: Double attributes not shown GameplayDebugger

UE - Gameplay - Gameplay Ability System - Aug 27, 2025

Context The Gameplay Ability System lets devs specify numerical attribute properties in UAttributeSet subclasses. Although the preferred attribute property type is FGameplayAttributeData, GAS has l ...

Geometry Collection's Chaos Cache Static Pose Scrubbing broken in 5.6 due to Custom Renderer GeometryCollectionRootProxyRenderer

UE - Simulation - Physics - Destruction - Aug 26, 2025

Geometry Collection's Chaos Cache Static Pose Scrubbing broken in 5.6 due to Custom Renderer GeometryCollectionRootProxyRenderer. The licensee has provided his analysis: In 5.6, when creating a Geo ...

Copy-pasting an actor property that is a set of strings adds extra quotes and escapes

UE - Editor - Workflow Systems - Aug 24, 2025

Copy-pasting an actor property that is a set of strings adds extra quotes and escapes. The licensee has reported: The problem doesn't happen for example for properties of types set of integers, nor ...

Adding pin to CR node causes crash if input variable is assigned to one of the array element

UE - Anim - Rigging - Control Rig - Aug 22, 2025

When a node has a variable assigned to one of its pins. You will get a crash every time you add a pin. I am sure this goes for all nodes with with the "add pin" functionality [Link Removed] ...