Crash when a Deferred Decal (Translucent) base material has a Nanite Override (Masked Surface) Material and the mesh has Nanite + Ray Tracing enabled.

UE - Graphics Features - Ray Tracing - Aug 14, 2025

A crash occurs when Nanite override material instance is used in a project with Ray tracing enabled where: 1 The Material assigned to the static mesh uses Deferred Decal / Translucent and the Nani ...

GenerateProxyMesh causes incorrect transform in ISM using Scale

UE - World Creation - Worldbuilding Tools - HLOD - Aug 20, 2019

MeshVertex has been converted by component transform before being converted by instance transform. It is ( Vertex * ComponentTransform ) * InstanceTransform. I thought it has to be converted by (Ve ...

Copy, Paste and Hover a Material Layer Blend Node causes Crash

Tools - Jun 25, 2015

In the Material Editor, if all Live Previews are turned off, copying and pasting a Material Layer Blend Node will crash when the tool tip is being processed. Also Reproduced in Main Promotable-CL-2 ...

FCDODiffControl doesn't properly account for lists of differing size.

UE - Gameplay - Blueprint - Sep 21, 2016

FCDODiffControl doesn't properly account for lists of differing size. The issues are marked in the following code:int IterOld = 0; int IterNew = 0; while (IterOld != OldProperties.Num() || IterNew ...

TickComponent and PostPhysicsTick in SkeletalMeshComponent can cause simultaneous read/write access

UE - Anim - Runtime - Jan 18, 2023

When a SkeletalMeshComponent is restarted by calling in order of   SetSimulatePhysics and SetComponentTickEnabled, the TickComponent and EndPhysicsTick are executed simultaneously. As a result, the ...

Lumen screen traces from hair cast noising moving shadows on faces

UE - Graphics Features - Lumen - May 17, 2024

There is moving blotchy noise on the head and face from hair when Lumen HZB tracing hits hair.  CL 33258050 fixes the noise in the hair, but tracing still hits hair when it starts from surfaces like ...

Many native-only interfaces incorrectly appear as implementable by blueprints

UE - Gameplay - Blueprint - Sep 14, 2020

Right now, any UINTERFACE that is not marked as CannotImplementInterfaceInBlueprint is shown as implementable in blueprint. If these functions have BlueprintCallable functions or related things then ...

Get and Set nodes for variables from a BP's parent class will not compile without a reference to Self (4.8)

UE - Gameplay - Blueprint - Jan 20, 2015

Get and Set nodes for variables from a BP's parent class will not compile without a reference to Self. Without one, the BP fails to compile with the following error: "Error Variable node Get NewVa ...

Get and Set nodes for variables from a BP's parent class will not compile without a reference to Self

UE - Gameplay - Blueprint - Jan 9, 2015

Get and Set nodes for variables from a BP's parent class will not compile without a reference to Self. Without one, the BP fails to compile with the following error: "Error Variable node Get NewVa ...

Slate-based Program targets assert on start up

UE - Editor - UI Systems - Slate - May 20, 2020

13431468 (which originated from FN) has caused Program-type targets to assert when starting. This has been observed with both UnrealInsights and UnrealFrontend. check(PrimaryDockArea.IsValid()) ...