Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker

UE - Graphics Features - Dec 12, 2025

If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...

[3ds max] Some geometry will display in all black in Path Tracer renders

UE - Editor - Content Pipeline - Datasmith - Exporters - Dec 12, 2025

Reported in SF [Link Removed] Some geometry from 3ds Max will display as all black when viewed in Path Tracer rendering. This effect is visible in both UE and Twinmotion. This was tested with Data ...

Iris - Ensure hit when destroying a torn off actor from AActor::TornOff

UE - Networking - Iris - Dec 11, 2025

As of CL 42014318, StopReplication requests that occur during ReceiveUpdate are delayed until all received data from the update is finished processing, including if the actor is torn off. However, i ...

PCG sampling of RVT does only works when sampling the first texture layer

UE - World Creation - Procedural Tools - PCG Component - Dec 11, 2025

The logic for selecting a page table texture in FVirtualTexturePageTable::Initialize() uses the indexing for texture layers (index 0-7) to fetch from the page table textures (index 0-1). All RVT for ...

Lumen HWRT "hit lighting" doesn't respect lighting channels

UE - Graphics Features - Lumen - Dec 10, 2025

Lumen hardware raytracing "hit lighting" doesn't respect lighting channels. See the provided repro project. Perhaps in 5.5.x, RT simply ignored non-channel-zero lights, but we didn't notice it prev ...

[ALT] - UE56 Editor launched with -AsyncLoadingThread will trigger MTAccess

UE - DEET - EditorLoader - Dec 10, 2025

When launching the editor with the -AsyncLoadingThread command, the engine uses an asynchronous thread to load and instantiate UObjects. At this point, if the instantiated UObject contains an FData ...

Replicated timeline may not call Finished event on client

UE - Networking - Dec 9, 2025

It seems this can happen if the timeline component on the client receives an update from the server for the final position of the timeline, causing it to be set as no longer playing before it has a ...

Convex hull generation fails when first 3 verts are colinear

UE - Simulation - Core - Dec 9, 2025

The licensee identified a number of cases where loading assets will trigger convex hull generation warnings:If the first 3 verts in the set are colinear (in which case IsPlanarShape() returns true b ...

[HORDE] Workspace does not respect stream view if the paths within the stream change to a newer CL then that of the stream

UE - Foundation - Horde - Dec 9, 2025

For example, if you have the engine in a different stream and specify an exact CL to use on the import path, you then update that import path to a later change with a higher CL number than that of t ...

Provided example Control Rig Python scripts that feature calls to GetControlRigBlueprint need to be updated to GetControlRigAssetInterface.

UE - Anim - Rigging - Control Rig - Dec 9, 2025

The unreal.ControlRigContextMenuContext.get_control_rig_blueprint() this function has been deprecated in Unreal Engine 5.7. As a result, the Python scripts included with the Control Rig plugin no ...