Unreal Engine Issues
Unreal Engine Issues
Changing MaterialQualityLevel causes a crash due to a ShaderMap mismatch in UniformExpressionCache
UE - Rendering Architecture - Materials - Nov 26, 2025A crash may occur when changing the MaterialQualitylevel via Scalability due to a race condition. The issue occurs because in ScalabilityCVarsSinkCallback(), when it creates the FGlobalComponentRec ...
Packaged version of VR Template does not launch in stereo mode by default
UE - Platform - XR - Nov 14, 2016The VR Template in 4.14 had a node in the level blueprint to enable stereo mode at the start of the game, but it has been removed in 4.15: [Image Removed] Maybe the "console command" wasn't the be ...
Lightmap Coordinate Index is not automatically set to 1 on import any longer with lightmap UV
UE - Editor - Content Pipeline - Import and Export - Sep 6, 2016When importing a static mesh with a second UV channel setup for the lightmap the second UV is no longer being automatically assigned as the lightmap coordinate index. In 4.12 the second UV detected ...
Cones for angular constraints not visible is Separate Translucency is disabled
UE - Graphics Features - Apr 14, 2016A user reported an issue where the cones that represent angular constraints in the PHAT editor are not rendered if Separate Translucency is disabled. This may be related to another issue with Separa ...
Auto Reimport crash with some file paths
UE - Editor - Content Pipeline - Import and Export - Dec 14, 2016Auto Reimport source paths can cause a crash with the editor. I couldn't narrow down in my limited testing what would cause the crash vs what would not with these file paths. The one in my attached ...
Alembic Geometry Cache is corrupted on reopening of project leading to crash
UE - Foundation - Core - Dec 20, 2016Alembic Geometry Cache crash when re-opening the project and a map that contains this asset or adding it to any existing/new levels will instantly crash the editor. This asset works correctly in the ...
Make/Break Struct node breaks for native structs after modifying the structure in a hot reload
UE - Foundation - Cpp Tools - Hot Reload - Apr 10, 2017Changing and compiling a custom struct in C++ will break behavior of Make/Break Struct nodes in blueprints if the blueprint is saved after the compile. Regression: No - blueprint fails to save afte ...
AI Controller Remains in World Outliner After Being Destroyed
UE - AI - Apr 18, 2017Destroying an AI Controller does not seem to remove it from the world. The controller will still remain in the World Outliner even after Destroy is called. Attempting to get the AI Controller after ...
Undoing pasting a component will crash ([CrashReport] UE4Editor_CoreUObject!FWeakObjectPtr::IsValid() [weakobjectptr.cpp:48])
UE - Gameplay - Components - Jul 20, 2017This is a common crash affecting users in 4.16. The callstack is similar to [Link Removed], which was fixed in 4.13. User DescriptionsAccidentally duplicated a blueprint with multiple static mesh ...
[CrashReport] UE4Editor_Kismet!FQuatRotationMatrix::FQuatRotationMatrix() [quatrotationtranslationmatrix.h:43]
UE - Gameplay - Aug 31, 2018User comment in crash group:Please Contact me to help fix this. I don't know what else to do. 41 FQuatRotationMatrix(const FQuat& Q) 42 ***** : FQuatRotationTranslationMatrix(Q, FVect ...