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: 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 ...

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

[Sequencer MRQ] Spatialized audio is not heard in MRQ renderings

Per customer case: [25102237 | Case | Salesforce|https://epicgames.lightning.force.com/lightning/r/Case/500QP00001V41PqYAJ/view] Audio that uses an Attenuation to set Spatialized Audio (just positi ...

PrepareTextureResources is being called repeatedly (on commandlets and potentially other cases)

Implement a commandlet that renders (with `-AllowCommandletRendering`) and frequently calls `CommandletHelpers::TickEngine()`.Have the commandlet load a map containing a world-partitioned landscape. T ...

VSM + Nanite Tessellation + Volumetric Fog Shadow leaking while the Directional lighting is rotating

Open Formats: Interchange Import - UCX Convex Hull Import Bug

When importing custom UCX collision meshes from FBX files into Unreal Engine, certain geometry profiles fail to generate correctly if the option "One Convex Hull Per UCX" is unchecked. The engine's ...