Ribbon Particle Normals are reversed from default Sprite Particles

UE - Graphics Features - Oct 13, 2015

It appears that the Vertex Normals from Ribbon Particles are opposite of what is expected via the Default Particle System given both systems share the same alignment (Facing Camera) [Image Removed] ...

Crash when merging Skeletal Mesh with incomplete LOD streaming

UE - Runtime - Deformable - Jul 24, 2026

SummaryMerging a Skeletal Mesh whose LOD streaming has not completed crashes with an AccessViolation while the vertex copy reads the Null buffers of LODs that have not been streamed inRoot cause is ...

Crash when Undo after deleting a Material Layer of a Material Instance.

UE - Rendering - Architecture - Materials - Apr 2, 2025

In Unreal Engine version 5.5.4, the Editor crashes when performing Undo after deleting a Material Layer of a Material Instance ...

Exporting a spawnable through Python doesn't work

UE - Anim - Sequencer - Jan 29, 2020

CppCompileWarningSettings.NonInlinedGenCppWarningLevel messages should contain Warning\Error

UE - Core - Cpp Tools - UnrealBuildTool - Oct 8, 2025

The messages emitted when CppCompileWarningSettings.NonInlinedGenCppWarningLevel is set to Warning\Error should contain the literal so the tools pick them up and react accordingly. From the EPS c ...

AutoLOD changes the static meshes LOD at different distances in VR Packages and Previews than in Editor

UE - Platform - XR - Jul 30, 2020

Packaged VR Projects and VR Previews change the LOD at a closer distance than in editor. ...

Crash with Twitch Live Streaming Plugin

UE - Foundation - Cpp Tools - Plugin System - May 12, 2015

The user is trying to get the Twitch LiveStream Plugin to work. After reading through some more recent Forum posts as well as the initial implementation of the Plugin within the release notes, it is ...

Steam Sessions fails to create when using the Create Session node

Docs - Nov 30, 2021

This is a Regression. 4.26.2 - Binary - no issue creating a session. 4.27.1 - Binary - no issue creating a session if you convert a previously working 4.26.2 project. 4.27.1 - Binary - Fails to c ...

On Instance Take Radial Damage will not receive radial damage against Foliage

UE - Gameplay - Jun 28, 2022

Different results in //UE4/Release-4.27 CL#18319896 On Instance Take Radial Damage will not receive radial damage against Foliage. ...

Anim notify issue with root motion replication

UE - Anim - Runtime - Jul 9, 2019

https://udn.unrealengine.com/questions/510965/view.html ...