Unreal Engine Issues

Crash when clicking "Reset to Default" button on the Details Panel for the MaterialAttributeLayers material node.

This crash repros from at least UE 5.3 and up to latest. The following assert is hit: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 1067] Array index out of bounds: 0 in ...

Editor/Details Panel allows duplicate keys in TMap/TSet UPROPERTY()

When edited through the Details Panel in the Editor, TMap and TSet properties should not allow duplicate keys. When those keys are USTRUCTs with the “WithIdenticalViaEquality” trait, this should be ...

Dithered LOD transitions sometimes briefly flicker to the next LOD before fading

When dithered LOD transitions occur, a brief flash of the next LOD level is first shown on the entire mesh after which the current LOD fades to the next (or previous) LOD. The flashing behavior only ...

Datasmith Export Bug with Camera Target

Potential bug was encountered when exporting vray cameras and their targets that have been path-constraint to corresponding splines. The resulting export file shows no camera targets; hence, missing ...

BlackboardComponent observer can be called for the wrong key

We need to, at least, prevent this by clearing observers when running a new BT using a different blackboard. Must also think that this might affect licensees relying on the current behavior (might h ...

ULevelSequence trying to duplicate a REINST_ class when creating new custom binding in ConvertOldSpawnables()

The assert that we're hitting is:Cannot replace existing object of a different class.  New Object: /Engine/Transient.REINST_BPC_NPC_VFX_C_230 /Game/Maps/[REDACTED]/Levels/[REDACTED]/LevelSequence/ ...

FPS drop (present time increase) when moving the editor windows to secondary screens

The licensee has mentioned that they also see an FPS drop without a second monitor, so this can happen just by separating windows out on the same screen. ...

Lumen ignores Landscape Holes (Landscape Visibility) when Hardware Ray Tracing is enabled and Ray Lighting Mode is set to Surface Cache

Context Lumen is the default global illumination and reflections system. Lumen renders diffuse interreflection with infinite bounces and indirect specular reflections in large, detailed environments ...

HLOD lightmap lost after level reopening with "save LODActors to HLOD Packages" option in project settings is on.

WasRecentlyRendered() and GetLastRenderTimeOnScreen() still triggers when a skeletal mesh re-enters the view frustum despite being occluded.

AActor::WasRecentlyRendered() and UPrimitiveComponent::GetLastRenderTimeOnScreen() both still trigger when a skeletal mesh (occluded behind a wall) re-enters the player's view frustum after being ou ...