"Move Selection to Current Level" can duplicate actors when cancelling

UE - World Creation - Worldbuilding Tools - Apr 17, 2026

When moving an Actor that is referenced in the source level, UEditorEngine::CopySelectedActorsToClipboard will try to select the Actor for delete which will pull the \"Delete Referenced Actor\" dial ...

Deadlock during cooking or editor in URigHierarchyController::AddElement on task thread while GarbageCollection occurs on gamethread.

UE - Runtime - Animation - Apr 15, 2026

In URigHiearchyController::AddElement (and other functions), arbitrary delegate code is called while holding Hierarchy->ElementsLock, through the Notify function. URigHierarchy::AddReferencedObject ...

[StateTree] Cannot use SetLinkedStateTreeOverrides if the linked asset uses the same schema with a parent context data class of the root tree.

UE - AI - StateTree - Apr 3, 2026

If both assets have the same schema (StateTreeComponentSchema), but the root tree has the Context Actor class set to Character and the linked asset is using a Context Actor class of Pawn. So the sch ...

CSM Cached Shadows missing when changing FOV

UE - Rendering - Graphics Features - Shadows - Mar 30, 2026

When changing the camera FOV with r.Shadows.CSMCaching enabled, the cached shadows don't appear to be used and shadows are missing. This occurs because the r.Shadow.RadiusThreshold can be low enoug ...

Issue with r.SkyAtmosphere.TransmittanceLUT.UseSmallFormat

UE - Rendering - Features - Mar 30, 2026

When "r.SkyAtmosphere.TransmittanceLUT.UseSmallFormat=1", some values for the Sky Atmosphere at some directional light angles can lead to the sun disk being cut off, and taking on a chord shape. A ...

Chaos Fields: LS_MasterField continuously creates components every frame and never cleans them up

UE - Runtime - Deformable - Mar 25, 2026

While active and ticking, the built-in FS_MasterField actor instance continuously creates several new components every frame, which are never cleaned up until the actor is destroyed. This can happen ...

WorldPartitionChangelistValidator incorrectly flags actors referencing the level script actor as invalid

UE - World Creation - Worldbuilding Tools - World Partition - Mar 23, 2026

When validating a change list that contains an actor that references the level script in the world (e.g. it has an event bound on the level script graph) it will fail changelist validation 100% of t ...

Editor crash in HairStrandsMeshProjection.cpp when spawning actor with Groom Component bound to skeletal mesh

UE - Gameplay Features - Character - Mar 23, 2026

The editor crashes with an assertion failure when placing a Blueprint actor that contains a Groom Component bound to a MetaHuman skeletal mesh. The crash occurs in AddHairStrandInitMeshSamplesPass d ...

Virtual Texture does not stream high-resolution data when assigned as a UI material to a widget.

UE - Rendering - Architecture - Mar 23, 2026

When a Virtual Texture is applied as a UI material, there is no associated geometry, so it does not explicitly request the loading of high-res virtual texture tiles. ...

Chooser with Gameplay tag as output causes Evaluate Choose to not compile.

UE - Characters - Animation - Mar 20, 2026

When using a No Primary Result Chooser that contains an FGameplayTag parameter, an Evaluate Chooser node using that chooser will cause a compilation error: LogBlueprint: Error: [AssetLog][PathToPro ...