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

UE - AI Workflows - UI Systems - Slate - Jun 4, 2026

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

UE - CAPT - Sequencer - Jun 2, 2026

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

UE - Graphics Tools - PCG - Graph - May 30, 2026

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: Editor preview don't show correct relative mesh transforms

UE - Engine Scaling - Mass - May 30, 2026

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

zComponent - Archive - May 29, 2026

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

[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 ...

AutoSize triggers ensure on shortened Skel Anim Section moved past anim length

zComponent - Archive - May 26, 2026

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

Lumen lighting in Presentations may appear darker than in Viewport

TM - Rendering - May 22, 2026

Reported in SF [Link Removed] In some scenes with Lumen enabled, interior scene lighting without direct lighting can appear drastically darker in Cloud Presentations than they do in the editor view ...

StreamingGeneration: Actor desc mutator phase now writes ActorDescView directly, breaking the cluster-invariant check in ValidateContainerInstanceDescriptors

UE - Engine Scaling - Streaming - World Partition - May 22, 2026

This report is from an EPS case: We hit a regression upgrading our project from 5.7 to 5.8. Map Check (and any other path that ends up calling UWorldPartition::CheckForErrors) assert inside FWorld ...