Many downloaded cloud items cause a performance issue when booting Twinmotion

TM - Interoperability - Sep 29, 2025

See slack thread: [Link Removed] Resume : In the context of the object substitution for Revit, when TM starts, it exports a csv listing the available objects and their corresponding thumbnail. This ...

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 ...

3D Grass may not appear in Path Tracer renders

TM - Rendering - Sep 19, 2025

Reported in SF [Link Removed] Path Tracer renders of images with 3D grass may not display 3D grass in the foreground of an image. The 3D grass material will not appear or may appear to cut off at s ...

Mutable references MetaHumans heads directly, but DNA Assets are private

UE - Anim - Mutable - Sep 18, 2025

When we switched our project to 5.6.1 This error appeared on build. The compilation of the Mutable assets in the editor is not reporting any issue. ...

Setting a struct bool property (bitfield) to itself writes the wrong value

UE - Framework - Blueprint Compiler - Sep 17, 2025

There's an issue when assigning a bitfield bool to a native bool in Blueprints. Currently, the engine erroneously treats the memory for a local bool as a uint8 bitfield, which is undefined behavior. ...

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 ...

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 ...