Hardware Lumen Surface Cache Artifacts on Nanite Geometry

UE - Graphics Features - Lumen - Sep 1, 2025

When using Hardware Lumen with Nanite-enabled meshes in UE 5.6+, black / dark surface cache artifacts appear that result in generally darker and unstable lighting. These artifacts are not immediatel ...

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues

UE - Simulation - Visual - Aug 30, 2025

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...

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 ...

UMG Retainer Box renders incorrect colors with Color Vision Deficiency enabled

UE - Editor - UI Systems - UMG - Aug 27, 2025

When using a Retainer Box in UMG with Color Vision Deficiency enabled, the content inside the Retainer Box is rendered with incorrect colors compared to the rest of the UI. This bug is present in UE ...

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 ...

StateTree : Crash when executing GetPropertyRef in SubTree linked via Linked Asset

UE - AI - StateTree - Aug 26, 2025

A crash occurs when GetPropertyRef node is executed from a SubTree that is linked within a StateTree, which itself has been linked from a parent StateTree via a Linked Asset ** . The processing con ...

BP Debugger: Unable to inspect debug data for ForEachLoop ArrayElement, Array_Get and Break Struct output pins

UE - Framework - Blueprint - Aug 26, 2025

Context The blueprint debugger allows you to trigger breakpoints and inspect the current state of variables, both member variables, local variables and persistent UberGraph variables. Problem The ...

Geometry Collection cluster handles leaking and causing ensures with field systems

UE - Simulation - Visual - Aug 26, 2025

Geometry Collection cluster handles leaking and causing ensures with field systems. The licensee has shared their analysis: We have been tracking down an assert that seems to happen occasionally wh ...