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 ...

5.5 Static Mesh Import Pipeline Regression

UE - Editor - Content Pipeline - Import and Export - Apr 25, 2025

This question was created in reference to: [Link Removed] This post references the first post because this problem was not discovered till now. I think it was masked because the issue appears to be ...

Switching project monitor with shift+win+arrow keys

UE - Rendering Architecture - RHI - Apr 24, 2025

Using Windows+Shift+Arrow keys to move the application window in Windowed Fullscreen from a low resolution monitor to a high resolution monitor does not resize the application window on a Windows 10 ...

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 ...

Missing material maps on user library objects created in TM 2022

TM - Core - Apr 23, 2025

Reported by user in SF [Link Removed] User library assets created in TM 2022.2.3 or older will not contain texture maps for their materials when the .tmi file is added to the TM 2025.1.1 User Libra ...