Color picker does not change the color of a Vector Parameter in a Material Instance until the mouse button is released

UE - Graphics Features - Mar 11, 2020

This is a regression from 4.23.1 (CL-9631420). The color picker does not update in realtime anymore when holding down the left-mouse button. Only on mouse-release does it update. This was reported ...

[Groom] Very thin hair has incorrect raytraced shadow on edges

UE - Graphics Features - Lumen - Jun 8, 2020

This only happens when 1) Hair Width is very small. e.g. 0.01 in the example 2) Light has raytraced shadow and Samples Per Pixel has a value > 1. e.g. 8 in the example The problem seems to be rel ...

Volumetric Clouds appear in front of foreground objects in the Right Eye of VR Headsets

UE - Platform - XR - Dec 15, 2021

It seems that volumetric clouds in the background appear in front of objects in the foreground in the right eye of a VR headset. I also tested in //UE4/Release-4.26 @ CL 15973114 and the results wer ...

Text to Speech does not work in Play in Editor

UE - Audio - Aug 18, 2022

This is not a regression as the TTS plugin isn't available in 4.27.2. Text to Speech does not work in Play in Editor, but does work in Stand Alone. A warning is thrown:LogSlateStyle: Warning: Unab ...

Static lights become stationary after toggling visiblity of level in packaged build

UE - Rendering - Graphics Features - Jun 11, 2025

In 5.5, there is a regression with baked lighting where static lights become stationary lights when a level is hidden and then made visible again. This happens in packaged builds and shows up as sta ...

Empty View Sets created when creating new images or panoramas

TM - Tools - Feb 16, 2026

Reported in SF [Link Removed] Starting in TM 2025.2, when creating new images or panoramas, a new View Set is created with each new image or panorama. These View Sets will not have any names and ca ...

FZipArchiveCompressTest failing to compile in non-editor Development builds

MetaHuman - Jul 28, 2026

`ZipArchiveTest.cpp` fails to compile for non-editor targets in Development configuration. `FZipArchiveCompressTest::RunTest` constructs `FZipArchiveReader`, which is editor only, but that section ...

Staging DLC is reportedly broken

UE - Foundation - Cpp Tools - Automation Tool - Dec 16, 2015

According to a licensee, StageFiles() is called with ExcludeWildcard that contains a directory name ("Engine/*") and bRecursive=true when building DLC. This is not supported by Directory.GetFiles(). ...

Spin box delta does not show update values correctly

UE - Editor - UI Systems - Dec 29, 2014

When setting the Spin box delta to 1 and the slider exponent to 1 the value of the spine box should go up by 1s. However, the actual value is still retains decimal points and is rounded to show whol ...

Creating and loading 1001+ instances of level crashes editor

UE - Editor - UI Systems - Localization - Aug 2, 2016

Creating and loading 1001+ instances of level crashes editor. Frequency: 4/4 Crashreporter: [Link Removed] Regression (yes) issue (does not) occur in 4.11.2 Notes While not reproduced internall ...