Unreal Engine Issues

UBackgroundBlur crashes at PSO creation under D3D12 SM6 when stereo rendering is enabled

Any Slate widget that triggers the Slate post-process blur (e.g., a UBackgroundBlur with non-zero strength) hits a fatal D3D12 CreateGraphicsPipelineState failure on first render. The fatal is funne ...

Crash in UWidgetAnimation::CreateDirectorInstance when switching resolution

Hello, We've encountered a crash in UWidgetAnimation::CreateDirectorInstance when repeatedly switching resolutions. We've had it for a while but it's not until recently that we've found a consisten ...

Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference

Context PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spa ...

Instanced Actors: Moving element in editor is not undoable

Context Instanced Actors can be moved by unchecking Lock Instance Locations on an IAM, and double-clicking into the actor → comp → instance to select an instance. Problem Moving an IA via the giz ...

Instanced Actors: Editor preview don't show correct relative mesh transforms

Context Actors can be converted into Instanced Actors via the IA plugin. During runtime and in the editor, an instanced actor’s visual is generated from the collection of StaticMeshComponents on th ...

Backout attempted fix for - AutoSize triggers ensure on shortened Skel Anim Section moved past anim length

In Sequencer, calling "Edit > Auto Size" on a UMovieSceneSkeletalAnimationSection triggers the LowerBound > UpperBound ensure in UMovieSceneSection::SetRange (MovieSceneSection.h:333) when the secti ...

[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]

#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...

Assert crash when playing Groom Cache with Card Mesh LOD

Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...

Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances

When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...

GameplayTagEventMap is cleared on clients when "AbilitySystem.Fix.ReplicateTagCountContainerWithIris" is enabled