Chaos Clothing CreateClothActor takes a long time with LODs and Self-Collision

UE - Simulation - Physics - Jan 21, 2024

Spawning an actor with Chaos cloth causes a hitch when LODs or Self-Collision are enabled on the cloth. LODs and Self-Collision seem to compound the issue. Self-Collision requires a collision simul ...

The Editor freezes during PIE when loading a .sav file from 4.7 in a 4.8 or 4.9 project

UE - Gameplay - Jun 24, 2015

The Editor freezes during PIE when loading a .sav file from 4.7 in a 4.8 or 4.9 project. The user reporting this reports a memory leak and crash, but I have not been able to reproduce that in partic ...

Enabling Merge GC Clusters and Blueprint Clustering causes a packaged Window project to crash

UE - Foundation - Core - Cooker - Jan 3, 2019

Enabling the check boxes for Merge GC Clusters and Blueprint Clustering causes packaged Windows projects to crash on startup. The log and dump files regarding this crash have been attached to this t ...

[AI] UE_MT_SCOPED_READ_ACCESS(NavElementAccessDetector) Fails in editor on fresh sync

UE - AI - Navigation - Jan 27, 2025

Licensees have reported failed multi-thread access code for NavElementAccessDetector in complex levels that have not finished compilation of their static meshes. The eventual failed check is inside ...

Sequencer Media Tracks trigger crash when an ImageSource is added

Media Framework - Jun 18, 2020

The same callstack appears in 4.24.3 (CL-11590370) but only when playing a Sequence with a Media Track that has a ImgMediaSource and Media Texture set on it. These repro steps work for 4.25 and 4.26 ...

Users project crashes when opening level that loads multiple sub-levels

UE - Foundation - Core - UObject - May 31, 2017

Users project crashes when opening level that loads multiple sub-levels. Unable to reproduce this in a clean project so the users project is provided though Epic's box account (link is in the repro ...

Compile error in ShadowDepthVertexShader.usf if INTERPOLATE_POSITION

UE - Graphics Features - Oct 21, 2015

Shader compile error in function PositionOnlyMain() in ShadowDepthVertexShader.usf if defined INTERPOLATE_POSITION. LogShaderCompilers:Warning: 1 Shader compiler errors compiling WorldGridMaterial ...

TMap does not serialize properly in specific circumstance when it contains a UObject property set to null by default

UE - Foundation - Core - Aug 8, 2018

A TMap containing a struct with a UObject reference property (set to nullptr by default) does not serialize properly for an instance where the UObject reference is set on the instance, but the TMap ...

Exporting process stuck in "Estimated time" phase when uploading projects with Panorama Sets & Presentation after freshly booting TM

TM - Core - Dec 4, 2024

Cloud Build: TWINMOTION CL app-2023.2.33001994-2024.1.37216540-2025.1.38508591-cloud-2024.12.02.095314 (DEV / STAG, CHROME) Issue: Exporting process stuck in "Estimated time" phase when uploading p ...

Assertion failed: ExportSettings == *ExistingExportSettings [File:D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Lightmass\Lightmass.cpp] [Line: 546]

UE - Graphics Features - Sep 12, 2023

Generated from CrashReporter Logs can be obtained via Crash Reporter ...