Runtime virtual texture sometimes shows corrupted tiles

UE - Rendering Architecture - Apr 28, 2025

Some licensees have reported seeing intermittent corruption of runtime virtual texture tiles. This hasn't been reproduced at Epic. Usually this shows up as some small percentage of rendered tiles l ...

A partially broken Geometry Collection ends up with garbage CollisionGroup data that can lead to strange behaviors

UE - Simulation - Physics - Destruction - Apr 27, 2025

A partially broken Geometry Collection (GC) ends up with garbage CollisionGroup data that can lead to strange behaviors. The licensee has noticed that a GC that goes thru a field applying ExternalS ...

Crash when exporting static mesh actor to FBX (Array index out of bounds)

UE - Editor - Content Pipeline - FBX - Apr 25, 2025

I set the Forced LOD Model on the mesh component > 1, then tried to export, this is what causes the crash. Here is my suggested fix, we just don't use Git or I'd do a PR: In the else() branch of FF ...

Engine no longer compiles after backporting RHI thread improvements and crash fix

UE - Rendering Architecture - RHI - Apr 24, 2025

Unreal Engine 5.4 code will no longer compile after applying both the RHI improvement code changes as described in [Link Removed] and the fix for the crash described in [Link Removed]. The compilati ...

Launching multiple Editor processes in UE 5.5 can throw warnings due to USD Core plugin initialization

UE - Editor - Content Pipeline - USD - Apr 23, 2025

Launching multiple Editor processes at the same time with the USD Core plugin enabled can cause warnings to be logged like the following:LogUsd: Warning: Failed to update LibraryPath for USD plugInf ...

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 ...

GAS: DefaultSubobject AttributeSet becomes invalid on duplicated blueprint

UE - Gameplay - Gameplay Ability System - Apr 22, 2025

When a native actor 'AMyActorClass' creates AttributeSets as a default subobject via CreateDefaultSubobject, duplicating an actor blueprint based on AMyActorClass will result in a blueprint with an ...

BSOD when launching Twinmotion on NVIDIA 50-series GPUs with 576.02 Drivers

TM - Rendering - Apr 22, 2025

Reported from multiple users. NVIDIA RTX 50-series GPU users are reporting BSODs when attempting to launch Twinmotion with the latest drivers installed. The crashes occur on the 576.02 driver versi ...