5.4, FRHIMemoryPool leaks memory

UE - Rendering Architecture - RHI - Feb 12, 2025

FRHIMemoryPool will leak data when it is destroyed. "FRHIMemoryPool::Init()" will create "FRHIMemoryPool::DesiredAllocationPoolSize" new "FRHIPoolAllocationData" objects, stored in "FRHIMemoryPool: ...

GPU Crash may occur when using Nanite Tesselation on landscape with several shadow casting local lights

UE - Graphics Features - Nanite - May 5, 2025

The GPU may time out in NaniteSplit when drawing VSM shadows for Nanite Tessellated landscape with in a scene with several local shadowed point lights. The issue doesn't reproduce in 5.6, likely to ...

Divergent group barriers in Lumen

UE - Graphics Features - Lumen - Apr 23, 2025

Intel reported GPU crashes on their hardware caused by divergent group barriers in ScreenProbeConvertToIrradianceCS:[numthreads(THREADGROUP_SIZE, THREADGROUP_SIZE, 1)] void ScreenProbeConvertToIrra ...

DiffuseIndirect_Lumen_3 parameter missing and causing crash with Screen Space reflections and Lumen Async Compute

UE - Graphics Features - Lumen - May 3, 2025

When the Reflection Method is set to Screen Space and Lumen reflections async compute is enabled Unreal will crash because DiffuseIndirect_Lumen_3 parameter missing, due to how DenoiserOutputs are o ...

Crash when changing window resolution with AMD GPU, D3D11 and renderoffscreen

UE - Rendering Architecture - RHI - Apr 9, 2025

Context A crash can be induced with running Unreal Engine with DirectX11, a AMD GPU and running -renderoffscreen flag, and the main window is resized. This issue was first observed with the PixelStre ...

Clay Render mode is not working with Modeling tools/Faces.

TM - Interoperability - Mar 10, 2025

[Image Removed] The Clay material is quite useful when the user needs to manipulate objects that originally has transparent materials, so not being able to use this feature on faces mode feels li ...

FHLSLMaterialTranslator::GetMaterialEnvironment can crash or not load UMaterialParameterCollections

UE - Rendering Architecture - Materials - Apr 30, 2025

In UE 5.5, the Editor may crash in FHLSLMaterialTranslator::GetMaterialEnvironment when loading materials with Material Parameter Collections, likely due to async loading. Calling ParameterCollectio ...

VisionOS deferred renderer regression

UE - Platform - XR - Sep 11, 2024

Deferred desktop renderer does not function correctly on visionOS.  It did work in 5.4.  One problem is the r.XRMSAAMode setting forcing 4 samples even when not using msaa, but there are other probl ...

Creating a GeometryCollectionActor from a GeometryCollectionAsset is ignoring some of the data set in the asset

UE - Simulation - Physics - Mar 13, 2025

When you create a GeometryCollectionActor by dragging a GeometryCollectionAsset from the ContentBrowser into the scene, instead of using the PhysicsMaterial defined in the GeometryCollectionAsset, i ...

Physics Constraint Component loss of accuracy

UE - Simulation - Physics - Mar 6, 2025

Physics Constraint Component has lost accuracy between Unreal versions 5.2 and 5.4 (and up). When measuring the exact distance between rigid bodies constrained by a Physics Constraint Component, the ...