Crash when opening a texture or editing its properties after stopping a preview in the material editor

UE - Rendering Architecture - Materials - Sep 5, 2025

When a texture asset has certain properties edited, its PostEditChangeProperty() method calls to UTexture::NotifyMaterials(), which triggers a recompilation of materials that reference it in their m ...

[Device Swap][Crash][Stadia] - Crash changing audio device from 5.1 to stereo

UE - Audio - Mar 10, 2021

There's a crash on stadia when changing the audio device from 5.1 to stereo. There's also a related issue where voice chat breaks when changing from 5.1 to stereo. The background is that CL14889950 ...

[CrashReport] UE4Editor-ApplicationCore.dylib!invocation function for block in FMacApplication::DeferEvent()

UE - Platform - Apple - Dec 1, 2017

This is an infrequent Mac crash in 4.18.1. Users have not provided any descriptions. Callstack from Log2017.11.27-02.08.07:839][947]LogMaterial: Missing cached shader map for material FLightmassMat ...

FixDeps runs on every build even without any changes

UE - Platform - Linux - Oct 21, 2016

This has been fixed for 4.15, but 4.14 was branched before the fix. Note that this issue is distinct from [Link Removed] and the fix is much simpler. Note that [Link Removed] (pull request #2839) ...

Resave commandlet broken when using BuildEnvironment = TargetBuildEnvironment.Unique;

UE - CoreTech - May 14, 2024

The explanation from the licensee seems pretty comprehensive. Text from the UDN: We've been trying to run fixupredirects via the resavepackages commandlet, but noticed that the OFPA assets were no ...

HTML5 packaging fails with Github couldn't verify LLVM version

UE - Platform - Mobile - Jun 21, 2016

Packaging code projects on Mac for HTML5 fails. A lot of Could not verify LLVM version warnings appear in the output log.[2016.06.21-22.27.10:488][413]UATHelper: Packaging (HTML5): UnrealBuildTool: ...

When moving actors to the current level, their label is reset and displayed incorrectly on the Scene Outliner until the next time it is refreshed

UE - Editor - Workflow Systems - Jul 14, 2025

This is a regression, it worked correctly up to UE 5.4, but repros on UE 5.5 and 5.6. Also, this seems related to [Link Removed], which was fixed by CL 40649716/40649749 and integrated into UE 5.6, ...

Geometry Collection (GC) fragments are affecting the Navmesh in wrong positions

UE - Simulation - Physics - Destruction - Dec 6, 2024

Geometry Collection (GC) fragments are affecting the Navmesh in wrong positions and the identified cause is wrong indexing. Once a GC breaks, it's fragments, when big enough, are creating islands in ...

When used with First Loop Start Frame Offset and Use Animation Blueprint, the character will alternate between the specified animation and the reference pose

UE - Anim - Anim in Engine - Jan 30, 2023

If you use StartFrameOffset set to 1 or higher in conjunction with the Use Animation Blueprint, the character's animation will be rough towards the end of the section. Specifically, it seems that th ...

Paper2D performance regression due to TArray resizing

UE - Graphics Features - Aug 16, 2019

We've noticed after upgrading our heavy Paper2D project to 4.22 that tilemap performance has been massively degraded compared to previous versions. After some digging we found out that it's due to a ...