Default Arm module in modular control rig set does not have an ik/fk switch that matches consistently.

UE - Anim - Rigging - Control Rig - Sep 14, 2025

We have built a modular Control Rig in Unreal 5.6, and while IK to FK matching works correctly in the rig, but we are facing an issue when applying mocap animation to the characters through the Leve ...

LODs with screen size 0 in legacy assets are incorrectly converted to 1 on load

UE - Graphics Features - Sep 11, 2025

When loading a mesh asset (static or skeletal) created in an old version of Unreal (e.g. 4.10), any LOD whose LOD screen size was originally set to 0, is converted to 1. This causes LODs that would ...

A 5.5 level that contains a Text3DComponent in a BP crashes the engine when opened in 5.6 (and up)

UE - Virtual Production - Sep 11, 2025

A 5.5 level that contains a Text3DComponent in a BP crashes the engine when opened in 5.6 (and up). The licensee has provided his analysis: Description: Level instance created in UE5.5 and re-saved ...

FD3D12BindlessResourceManager::GrowCPUHeap will cause GPU heap activation whether it's needed or not

UE - Rendering Architecture - RHI - Sep 11, 2025

The ctor of FD3D12BindlessResourceManager implies that GPU heap activation is intended to occur lazily with ERHIBindlessConfiguration::RayTracingShaders, however any call to FD3D12BindlessResourceMa ...

Enabling STATS causes RenderThread to wait for GPU

UE - Rendering Architecture - RHI - Sep 10, 2025

The licensee noticed that in Development builds, the Render thread times are suspiciously similar to GPU times, and the same thing happens when enabling FORCE_USE_STATS in Test configuration. The is ...

Landscape Layer Blending Painting Issue

UE - Graphics Tools - Terrain - Sep 10, 2025

There are two issues when painting landscape layers.Paint: When painting between different layers, square-shaped artifacts or splotches appear.Fill Layer: The blended weights of other layers aren't ...

SkyLight Leaking does not affect reflections when the SkyLight is static but static lighting is disallowed

UE - Graphics Features - Sep 10, 2025

Reflections do not receive SkyLight leakage contribution from a static SkyLight when static lighting is disallowed. This is caused by the function UpdateSkyIrradianceGpuBuffer checking if the SkyLig ...

Crashes occur when executing MRQ while adding UMG with RetainerBox.

UE - Editor - UI Systems - Slate - Sep 9, 2025

Create an asset containing a RetainerBox in UMG, then add the created UMG to the viewport using AddViewport. Running MRQ after this causes a crash. ...

Undoing keyframe addition in Sequencer unselects actors in the Outliner

UE - Anim - Sep 8, 2025

When a keyframe is added to a track in the Sequencer, undoing the operation correctly removes the keyframe, but it also unselects the actor. This becomes especially inconvenient when multiple actors ...

ensure(PinHelpers::UnresolvedPins.Num() == 0); fails after undoing in the editor

UE - Framework - Blueprint Editor - Sep 6, 2025

The underlying cause is some edge case involving a math expression node, which does some perhaps naive things with a contained graph. ...