Unreal Engine Issues
Unreal Engine Issues
[WorldPartition][CellTransformer] ISM Cell Transformer breaks component hierarchy when child component are transformed
UE - World Creation - Worldbuilding Tools - World Partition - Dec 15, 2025This case is related to [Link Removed] Closed but is not a duplicate. Please make sure to download the attached project a ...
[3ds max] Some geometry will display in all black in Path Tracer renders
UE - Editor - Content Pipeline - Datasmith - Exporters - Dec 12, 2025Reported 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 - BeginPlay not called on client for statically placed, low-priority replicated actor
UE - Networking - Iris - Dec 11, 2025On the client, NotifyBeginPlay is triggered via AGameStateBase::OnRep_ReplicatedHasBegunPlay. However, if a replicated actor is waiting on its initial replicated state to be received and applied (bA ...
Replicated timeline may not call Finished event on client
UE - Networking - Dec 9, 2025It 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, 2025The 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, 2025For 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 ...
Drag and Drop fails in Standalone and Packaged builds when WidgetComponent’s Widget is set at runtime
UE - Editor - UI Systems - Dec 4, 2025When a UWidgetComponent has its widget assigned dynamically at runtime using CreateWidget and SetWidget, drag & drop operations fail in Standalone Game and packaged/game builds, while working correc ...
Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled
UE - Rendering - Architecture - RHI - Dec 3, 2025When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...
Standalone Level Instance with WorldPartition world don't load in editor
UE - World Creation - Worldbuilding Tools - Level Instances - Dec 2, 2025A WorldPartition map used as a level instance that's set to standalone mode doesn't load its actors in the editor. ...
Blueprints can enter a corrupted state where Actors construct DefaultSubobjects using CreateOptionalDefaultSubobject, even though child classes call DoNotCreateDefaultSubobject
UE - Framework - Blueprint - Nov 28, 2025Blueprints can enter a corrupted state where Actors construct DefaultSubobjects using CreateOptionalDefaultSubobject, even though child classes call DoNotCreateDefaultSubobject. In some situations, ...