Unreal Engine Issues
Unreal Engine Issues
A build may fail in Visual Studio if a space is added after the # in an include pre-processor instruction to allow a struct in one header file to reference a struct in the other
UE - Foundation - Core - Sep 23, 2016A project building in Visual Studio will sometimes fail with the error Unrecognized type 'FBar' - type must be a UCLASS, USTRUCT or UENUM. This can occur in situations where one struct was reference ...
Hot Reload crash on PIE with custom AIController and Perception Component
UE - AI - Sep 29, 2015If a pawn in the level is using a custom AI Controller that sets the AIPerceptionComponent in code, the editor will crash on PIE after a hot reload. CrashReporter: [Link Removed] ...
StartCameraFade() breaks on mobile projects after editor is closed/reopened
UE - Platform - Mobile - Oct 6, 2015If a project that is set to Mobile/Tablet and Scalable 3D or 2D uses StartCameraFade() to produce a fade in effect, the effect will not play in PIE if the editor is closed/reopened. ...
Crash when merging Skeletal Mesh with incomplete LOD streaming
UE - Runtime - Deformable - Jul 24, 2026SummaryMerging a Skeletal Mesh whose LOD streaming has not completed crashes with an AccessViolation while the vertex copy reads the Null buffers of LODs that have not been streamed inRoot cause is ...
Crash when Undo after deleting a Material Layer of a Material Instance.
UE - Rendering - Architecture - Materials - Apr 2, 2025In Unreal Engine version 5.5.4, the Editor crashes when performing Undo after deleting a Material Layer of a Material Instance ...
Mesh painting on staticmesh doesn't always apply Colors to All LODs
UE - Editor - Content Pipeline - Asset Build - Apr 18, 2022See the video [Link Removed] ...
Exporting a spawnable through Python doesn't work
UE - Anim - Sequencer - Jan 29, 2020Possible bug with GAOGlobalDistanceFieldCacheMostlyStaticSeparately
UE - Rendering - Graphics Features - Jun 2, 2025The Global Distance Field can constantly update, even when the camera is stationary, in large World Partition maps. This bug requires a large amount of the World Partition map to be loaded to reprod ...
CppCompileWarningSettings.NonInlinedGenCppWarningLevel messages should contain Warning\Error
UE - Core - Cpp Tools - UnrealBuildTool - Oct 8, 2025The messages emitted when CppCompileWarningSettings.NonInlinedGenCppWarningLevel is set to Warning\Error should contain the literal so the tools pick them up and react accordingly. From the EPS c ...
AutoLOD changes the static meshes LOD at different distances in VR Packages and Previews than in Editor
UE - Platform - XR - Jul 30, 2020Packaged VR Projects and VR Previews change the LOD at a closer distance than in editor. ...