Mutable constant texture variable with ClipUV mask only works with new experimental dynamic variable is connected as well

UE - Anim - Mutable - Sep 22, 2025

We are attempting to use Mutable in 5.6.1 and have encountered an issue which we are not sure how to resolve. The issue occurs when using the ClipWithUVMask node. In short we have a customizable o ...

Calling FOnlineIdentitySteam::GetLinkedAccountAuthToken without an internet connection won't execute callback delegate for WebAPI token type

UE - Online - Sep 22, 2025

For the "WebAPI" TokenType, the call to execute the delegate is missing in the case where the SteamUserPtr is null or if BLoggedOn is false for the SteamUserPtr, so GetLinkedAccountAuthToken will ju ...

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 ...

Changing per layer parameters in a layered material that writes to RVT can cause temporary visual corruption

UE - Rendering Architecture - Sep 12, 2025

When using a layered material that writes to a runtime virtual texture. Sometimes when modifying a layer parameter in the material instance editor. The cached material data in the runtime virtual ...

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 ...