FBX Import flips faces of mesh on Import for static meshes

UE - Graphics Features - Jan 29, 2016

User is reporting that this is happening with some, but not all meshes. I didn't see anything out of the ordinary when looking at the asset in 3Ds Max, and the asset will import correctly into 4.10. ...

"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 ...

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 ...

POM material triggers Video Driver Crash

UE - Graphics Features - Apr 26, 2016

When a POM decal material is applied to a decal actor in the scene the video driver will crash. This worked prior to 4.11.0 release. Only when the material is assigned to a decal actor will the vide ...

Connecting a Client to a Server in PIE with Auto Connect to Server disabled will crash the editor

UE - Networking - Feb 22, 2016

Connecting a Client to a Server in PIE with Auto Connect to Server disabled will crash the editor. EDIT: simple test project attached. Make sure Auto Connect to Server is disabled, and PIE with 2 p ...