Compatible Skeleton Animation does not retarget the same on duplicate skeleton

UE - Anim - Rigging - Retargeting - Jan 29, 2026

If a mesh is exported from the engine, reimported as a new skeleton and mesh, and then marked as a compatible skeleton. Animation will have slightly different rotations playing on the skeleton. ...

Crash when enabling Nanite on a Mesh using an OptimusDeformer

UE - Anim - Rigging - Deformer - Jan 29, 2026

When a skeletal mesh has a deformer present and then nanite support is enabled and applied. (the deformer in question was hsasset://DeformerGraph/Deformers/DG_LinearBlendSkin_Morph_Cloth_RecomputeNo ...

Incorrect geometry for OnMouseMove event on Slider with RightToLeft flow direction

UE - Editor - UI Systems - Slate - Jan 28, 2026

When a slider is in RTL flow direction, and thus its position is changed, the handle is not drawn at the correct position during mouse drag. Instead, the handle draws as if the slider was not moved ...

Textures from Data tables do not work with Clip with UV Mask.

UE - Anim - Mutable - Jan 23, 2026

Currently this workflow fails to generate in mutable, but using static paramters for textures do work. ...

PCG Volume does not regenerate after being moved through a sequencer sequence

UE - World Creation - Procedural Tools - PCG Component - Jan 23, 2026

Any transform modifications on the PCGVolume by Sequencer use USceneComponent::SetRelativeTransform directly and are not tracked by the TrackingManager (FPCGTrackingManager::OnObjectPropertyChanged ...

Texture streaming uses ISM component bounds instead of closest ISM instance

UE - Rendering Architecture - Jan 22, 2026

When regular texture streaming is used (not virtual textures), the largest mips are always loaded for ISM mesh textures whenever the camera is inside the bounds of the ISM even if the instances are ...

PCGs Duplicate Point node option to apply in Relative Space has metadata warnings and crashes editor.

UE - World Creation - Procedural Tools - Jan 21, 2026

When 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 ...

UEditorEngine::OnAllPIEInstancesStarted() called prematurely, multiple times, while PIE clients are starting

UE - Gameplay - Jan 21, 2026

Context 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 - Gameplay - Jan 21, 2026

Display 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, 2026

UReplicationGraph::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 ...