Unreal Engine Issues
Unreal Engine Issues
Particle Random Value is the same for all particles with a Niagara Mesh Renderer
UE - Rendering - Architecture - Niagara - Sep 28, 2026A material using the Particle Random Value node returns the same value for every particle drawn by a Niagara Mesh Renderer. Particle transforms are not affected, only the random value. This happens ...
[Niagara][5.8] Data Channel Read and Write register with an identical type hash when fx.Niagara.DataChannels.Enabled is set from ini, hitting checkf in FNiagaraTypeRegistry::RegisterTypeInternal
UE - Rendering - Architecture - Niagara - Sep 28, 2026Affects: 5.8 (verified on Release-5.8), Windows, EditorSummary Adding fx.Niagara.DataChannels.Enabled=true to an ini file makes the Niagara editor assert when a Data Channel Read is created. The sa ...
Light Function and Post Process domain material thumbnails show the default material
UE - Rendering - Architecture - Materials - Sep 25, 2026Since 5.8, materials whose Material Domain is Light Function or Post Process no longer preview correctly in the editor. They render as the default material (WorldGridMaterial) instead of the materia ...
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 ...