"Combine Meshes" Breaks Material Slot Assignment

Tools - Jan 18, 2017

When importing an FBX with several different meshes and multiple materials with "Combine Meshes" enabled the materials will get assigned to incorrect portions of the mesh. I've included a version o ...

Buffer Visualization for DecalMask is missing

UE - Graphics Features - Feb 29, 2016

The Buffer Visualization for DecalMask is no longer an option. Also, when looking at the Buffer Visualization Overview the DecalMask slot has been removed. See attached image for comparison Worke ...

Crash after network disconnection/pulling network cable

UE - Networking - Jul 11, 2019

A very unfortunate bug shipped in 4.22 that causes a crash in many cases when a client is disconnected from the network, such as when unplugging the network cable. This will be a cert failure on con ...

Landscape Layer Blend generates bad code for preview shader

UE - LD & Modeling - Terrain - Landscape - Sep 23, 2019

It breaks only when compiling the preview shader. Adding a preview weight to the Layer0 on the Layer Blend node fixes the problem. The source of the bug is in UMaterialExpressionLandscapeLayerBlend ...

Cash when entering Path Tracing view mode if r.Decal.NormalReprojectionEnabled true

UE - Graphics Features - Path Tracer - May 16, 2025

Cash when entering Path Tracing view mode if r.Decal.NormalReprojectionEnabled true The licensee has reported: This crash happens because the DeferredShadingRenderer tries to extract the normal GBu ...

DataTable::LoadStructData allocating wrong size

UE - Foundation - Core - Oct 5, 2016

Pointed out by a licensee here: UDataTableを読みこんだ際のメモリ破壊について When reading the `UDataTable, in DataTable::LoadStructData()` the contents of the struct are interpreted[Image Removed], but the size of ...

Scaling snap for selected object are reset to the origin of the scale pivot location

Tools - Apr 27, 2016

When scaling multiple selected actors in the scene with snap enabled the actors will reposition to the pivot origin of the last selected actor in the group when going down to a value of 0 or a negat ...

UDN : Mutable Trying to Access Invalid UEdGraph Pointer

UE - Anim - Mutable - Mar 6, 2025

Hello, We've started seeing a crash within Mutable when it tries to access the source graph in PIE. This only seems to be a problem when running a dedicated server as a separate process. We integra ...

Manipulating Morph Target on Master Component distorts Slave Components

OLD - Anim - Apr 1, 2016

Manipulating Morph Targets on Master Component distorts Slave Components. It makes no difference if the slave component has the morph target being manipulated in the master See attached image and ...

Particle Cutout Will Clip Texture On Certain Frames Even With Alpha Threshold of 0.0001

UE - Niagara - Feb 17, 2017

A licensee has reported that the particle cutout feature will sometimes clip the image on some frames despite having an alpha threshold of 0.0001 The attached project has an example of this on the ...