Merge Actors (Simplify) is broken with Substrate Shader Models Node

UE - Graphics Features - Substrate - Sep 29, 2025

Substrate Materials cannot be baked when Meshes are merged using the "Simplify" method. All textures except for the normal are reduced to a single black parameter. The normal texture produced does n ...

Mutable custom versioning issue from 5.5->5.6

UE - Anim - Mutable - Sep 19, 2025

In 5.6, a handful of new entries in `FCustomizableObjectCustomVersion` were added, including `SetDisplayNamePropertyAsPinNameOfTableNodes`. Looking back at the history, `SetDisplayNamePropertyAsPinN ...

Nanite Skeletal Meshes Invalidate VSM

UE - Graphics Features - Nanite - Sep 17, 2025

Nanite Skeletal Meshes will always invalidate VSMs, even with their Shadow Cache Invalidation Behavior set to Rigid. This does not match the behavior of non-Nanite Skeletal Meshes. ...

Custom fallback mesh LODs for Nanite-enabled meshes not working

UE - Graphics Features - Nanite - Sep 15, 2025

Creating a custom fallback mesh with LOD for Nanite-enabled meshes with multiple materials, results in mesh LODs with errors. As the number of material sections (material slots) decreases with coars ...

FBX reimport issue with Interchange Framework

UE - Editor - Content Pipeline - Import and Export - Sep 15, 2025

A licensee has reported that the following repro steps can result in a "Failed to merge bones" error:One of our Skeletal Mesh assets was imported into engine version 5.4 using an older version of th ...

LODs screen sizes in legacy assets are incorrectly converted to all have the same value on load

UE - Editor - Content Pipeline - Sep 11, 2025

When loading a static mesh asset created in an old version of Unreal (e.g. 4.10), all LODs have their Screen Size property set to the same value (approximately 1.5). This happens because the static ...

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 ...