Unreal Engine Issues
Unreal Engine Issues
ResolvedView.DirectionalLightColor and DirectionalLightDirection go black when one of several directional lights is removed from the scene
UE - Rendering - Features - Sep 25, 2026With more than one directional light in the scene, ResolvedView.DirectionalLightColor and ResolvedView.DirectionalLightDirection can report the wrong light, or black and a zero vector, while a direc ...
Update prepackaged dotnet to latest 10 patch release due to crash on Mac OS.
UE - Platform - Mac - Sep 24, 2026A dotnet crash occurs sporadically with a sigsev or sigbus when running on Mac OS. This is in the dotnet executable itself, and can happen on commands like `dotnet build`, not just on executing the ...
Editor hangs for several seconds when closing multiple asset editors
UE - Editor - Sep 24, 2026CL 51680020 added an async write in SStandaloneAssetEditorToolkitHost::SaveTabLocation(). This can cause multi-threaded write conflicts on EditorPerProjectUserSettings.ini. As a result, the file mov ...
Widget animations queued before Slate creation are not carried out in UE5.8
UE - ACT Character - Sequencer - Sep 24, 2026We are currently upgrading some of our systems from Unreal 5.6 to Unreal 5.8, and we've noticed an issue with Widget animations. In one of our commonly used actors, a Widget animation is queued in t ...
Foliage painted on Mesh Terrain disappears after edits are made
UE - Graphics Tools - Mesh Terrain - Sep 22, 2026Mesh Terrain recreates the visible section actors when edits are made, and those sections in the editor don't correspond to the ones at runtime, which breaks the ComponentId that the foliage system ...
Enhanced Input: use-after-free in EvaluateInputComponentDelegates when a delegate forces a synchronous mapping rebuild
UE - Gameplay - Input - Sep 21, 2026Context UEnhancedPlayerInput::EvaluateInputComponentDelegates iterates the delegates that triggered this tick. For each one it resolves the action's state via FindActionInstanceData(DelegateAction) ...
Static Mesh Decals flicker when ISM components with same material are in frame
UE - Rendering - Architecture - Sep 21, 2026When using a Deferred Decal material on an assets with ISM Runtime Cell Transformers, flickering occurs when static mesh and instanced static mesh components are in the frame using the same decal ma ...
ReturnUntouchedSceneColorForPostProcessing ignores view overrides and breaks splitscreen
UE - Rendering - Architecture - Sep 17, 2026When a view extension uses ReturnUntouchedSceneColorForPostProcessing and uses split screen, the final view is incorrect (clipped) because ReturnUntouchedSceneColorForPostProcessing doesn't take int ...
Linux Crash Reporter can fail due to exceeding crash malloc space when generating the report
UE - Platform - Linux - Sep 16, 2026On Linux a crashing process can fail to produce a crash report at all. The crash folder is created and contains CrashContext.runtime-xml and Diagnostics.txt, but the copied log file is 0 bytes, Cras ...
Unexpected offset when using attach tracks with scene root components
UE - ACT Character - Sequencer - Sep 15, 2026We noticed an inconsistency when using attach tracks, depending on whether or not the parent actor has a default scene root. This creates an unintuitive behaviour for animators. It can be reproduce ...