Unreal Engine Issues
Unreal Engine Issues
StaticMesh export to FBX crashes if UVElements has more channels than VertexInstanceUVs
UE - Editor - Content Pipeline - FBX - Jan 22, 2026As indicated in the repro steps, we have a StaticMesh asset that, for some reason, has a mismatch in their serialized bulk data where:MeshDescription->GetNumUVElementChannels() == 2FStaticMeshConstA ...
Custom Primitive Data is not affected in the skeletal mesh on BP instances in the editor
UE - Rendering Architecture - Jan 22, 2026Editing Custom Primitive Data values in the details panel of a placed BP actor with a Skeletal Mesh component does not reflect in the Editor viewport. ...
PCGs Duplicate Point node option to apply in Relative Space has metadata warnings and crashes editor.
UE - World Creation - Procedural Tools - Jan 21, 2026When using the PCG Duplicate Point node's "Direction Applied in Relative Space" option, this deletes or messes with the output metadata and, if connected to an output or using it's debug mode, will ...
Memory leak in FMaterialPSORequestManager
UE - Rendering Architecture - RHI - Jan 21, 2026Context: FMaterialPSORequestManager::PrecachePSOs() is called at runtime when an asset utilizing a material is loaded. This occurs during engine init, travel, and when any async or synchronous load ...
Rotated RetainerWidget does not account for rotation during hit testing
UE - Editor - UI Systems - Jan 21, 2026Hit testing for widgets contained within a RetainerWidget does not correctly account for rotation applied via render transforms . While the content renders with the expected rotation, hover and clic ...
UEditorEngine::OnAllPIEInstancesStarted() called prematurely, multiple times, while PIE clients are starting
UE - Gameplay - Jan 21, 2026Context UEditorEngine::OnAllPIEInstancesStarted() is a virtual function that gets called when launching Play-in-Editor. It can be overridden if the game project chooses to introduce a subclass of U ...
When Constrain Aspect Ratio is enabled, the display position of DrawDebug rendering becomes misaligned
UE - Editor - Developer Usability - Jan 21, 2026Display DrawDebugSphere at the DefaultPawn's positionSet bConstrainAspectRatio=true on the DefaultPawn's CameraComponent Setting bConstrainAspectRatio=true in CameraComponent causes DrawDebug renderi ...
Multicast RPCs may be sent to clients in a different level with Replication Graph
UE - Networking - Jan 20, 2026UReplicationGraph::ProcessRemoteFunction does not check if the client has the same loaded world as the server when sending a multicast RPCs. For actors that are persisted partway through a seamless ...
Sequencer: Camera blends restore to incorrect view target after Keep State
UE - Anim - Sequencer - Jan 20, 2026When a Level Sequence’s Camera Cut track with When Finished = Keep State is played, the “original state” is persisted into the PreAnimatedStorage array inside FPreAnimatedCameraCutStorage. From the ...
Material Analyzer misreports static params for Material Layers
UE - Rendering Architecture - Materials - Jan 20, 2026When analyzing materials that use Material Layers, Material Analyzer reports that multiple Material Instances “share the same static parameter array” and therefore recommends reparenting so that onl ...