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 ...

Forced reboot launching editor the first time

UE - Foundation - Cpp Tools - May 30, 2018

Note that before I tried running the editor via the Launch button, I just happened to run the Editor exe directly, and this did not repro then. After my PC rebooted I tried to reproduce it again an ...

LODs screen sizes in legacy assets are incorrectly converted to all have the same value on load

UE - Editor - Content Pipeline - Sep 11, 2025

When loading a static mesh asset created in an old version of Unreal (e.g. 4.10), all LODs have their Screen Size property set to the same value (approximately 1.5). This happens because the static ...

Get All Actors of Class is failing to report at Event Begin Play in a streamed level

UE - Gameplay - Sep 3, 2015

Get All Actors of Class is failing to report at Event Begin Play in a streamed level. Test project attached. This is a regression: did NOT occur in 4.8.3. Reproduced in 4.9.0 binary and Main (2678 ...

UV Rotation does not work for video materials

TM - Rendering - Dec 9, 2024

The rotation parameter of video materials does not function in Twinmotion 2024.1.2 and Twinmotion 2025.1 PR. Adjusting the slider does not have any effect. Feature last worked in Twinmotion 2023.2 ...

Debug Helpers no longer drawn indefinitely if life time is set to 0 or less

UE - Graphics Features - Sep 10, 2018

Setting the lifetime for one of the visual debug helpers (a sphere was used in the repro, but the results should be similar for any of the debug helpers) to a value of 0 or less should make the debu ...

Packaging with plugins GearVR and GoogleVR together cause build failed with multiple definitions of GetHMD()

UE - Platform - XR - Sep 7, 2016

Packaging with plugins GearVR and GoogleVR together cause build failed with multiple definitions of GetHMD(). Log attached for build error and error portion plugged into the callstack box. ...

Virtual Memory leak when using specific rendering settings in the template project

UE - Rendering Architecture - Dec 20, 2025

When a project is run with these settings in a template project, untracked virtual memory increases. Cvars r.GBufferFormat 3 r.Lumen.TraceMeshSDFs 1 r.Lumen.TranslucencyReflections.FrontLayer.Enab ...

Server Travel from Map A to Map B then back to Map A will crash on exiting PIE

UE - Gameplay - Jul 10, 2015

Server Travel from Map A to Map B then back to Map A will crash on exiting PIE. Generates different call stacks between 4.8.1 and Main. Crash Reporter: 4.8.1: [Link Removed] Main: [Link Removed] ...

HTML5 shows up as black screen in FireFox 32-bit

UE - Platform - Mobile - Apr 16, 2015

Packaged HTML5 games are not running on FireFox 32-bit Version 37.0.1; Some projects will also provide you with a scripting error that appears when you attempt to run the game on 37.0.1 Spoke with ...