Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled

UE - Rendering - Architecture - RHI - Dec 3, 2025

When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...

Pass names appear as "RDGEvent" in Unreal Insights when r.rhisetgpucaptureoptions=1

UE - Rendering - Architecture - RHI - Dec 2, 2025

When capturing a trace in Unreal Insights, all r.rhisetgpucaptureoptions=1 (r.RDG.Events=3) all RDG pass events appear simply as RDGEvent, without the actual name due to the logic for RDG_EVENT_SCOP ...

FStateTreeRunParallelStateTreeTask and TStateTreePropertyRef

UE - AI - StateTree - Dec 2, 2025

When using a state tree that has a StateTreePropertyRef as a parameter in parallel any references will fail to resolve using the GetPropertyRef node. ...

Not all MidPhases are enumerated in TSimCallbackObject::OnMidPhaseModification

UE - Simulation - Core - Dec 2, 2025

Newly generated MidPhases are copied into the array accessible in the NarrowPhase after the OnPreSimulate callback is invoked. As a result, it is not possible to modify newly created MidPhases withi ...

Blueprints can enter a corrupted state where Actors construct DefaultSubobjects using CreateOptionalDefaultSubobject, even though child classes call DoNotCreateDefaultSubobject

UE - Framework - Blueprint - Nov 28, 2025

Blueprints can enter a corrupted state where Actors construct DefaultSubobjects using CreateOptionalDefaultSubobject, even though child classes call DoNotCreateDefaultSubobject. In some situations, ...

Memory leak in Landscape edit mode

UE - Graphics Tools - Terrain - Landscape - Nov 28, 2025

SaveGeneratedTexture2DAsset can crash when overwriting an existing asset

UE - Texture - Nov 28, 2025

SaveGeneratedTexture2DAsset can crash for a variety of reasons when overwriting an existing texture asset. When no existing asset exists, the function simply moves the provided transient Texture ass ...

Crash when Live Coding is triggered after engine source edits Blueprints using ChildActorComponent

UE - Framework - Blueprint - Nov 28, 2025

After editing engine source files and triggering Live Coding, derived Blueprints that inherit from a Blueprint containing a ChildActorComponent cause UChildActorComponent::Serialize to run on a Live ...

Morph target normals not correctly applied when imported as LOD 0

UE - Editor - Content Pipeline - FBX - Nov 27, 2025

This is a regression since 5.5 with skeletal meshes where morph target normal/tangent deformation only works when a mesh is imported as a LOD of an existing skeletal mesh, but not when imported as L ...

Changing MaterialQualityLevel causes a crash due to a ShaderMap mismatch in UniformExpressionCache

UE - Rendering - Architecture - Materials - Nov 26, 2025

A crash may occur when changing the MaterialQualitylevel via Scalability due to a race condition. The issue occurs because in ScalabilityCVarsSinkCallback(), when it creates the FGlobalComponentRec ...