UI transparency breaks when dragging a game window around the screen

UE - Editor - UI Systems - Nov 20, 2017

When a game window launched from UE is moved around the screen, any transparent elements on the screen will turn fully opaque. The loss of transparency also causes some text to become blurry. This d ...

Frame 0 event does not get triggered when using SetPlaybackPosition

UE - Anim - Sequencer - Apr 17, 2018

An event at frame 0 of a sequence does not seem to get called when using "SetPlaybackPosition 0" to reset the playback position to the start. This seems to be a regression. 4.17.2, the frame 0 even ...

No Dynamic Shadows on Translucent Materials in iOS Preview

UE - Platform - Mobile - Jul 23, 2018

There are no dynamic shadows on translucent materials in the "iOS Preview" for the preview rendering level. Working as intended in 4.16 CL# 3561208, 4.17 CL# 3658906, and 4.18 CL# 3832480. Found i ...

Certain materials are overly bright with Ray Traced Global Illumination denoiser

UE - Graphics Features - Lumen - Mar 14, 2019

Ray Traced Global Illumination is causing some materials to glow extremely bright Disabling r.raytracing.globalillumination.denoiser fixes the issue In 4.22 preview 5 binary (5365847) the result i ...

Arrays of Soft Object local variables are not captured for reference graph

UE - Gameplay - Blueprint - May 20, 2019

This bug comes from https://udn.unrealengine.com/questions/492861/view.html and is a very similar problem to [Link Removed] The issue is that the code that harvests soft object references stored in ...

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 ...

PlayerCollision visualization incorrect on LandscapeSplineMesh when Nanite is enabled

UE - Rendering - Features - Nanite - Dec 3, 2025

From licensee: I’ve found an issue with the visualization of PlayerCollisions when using LandscapeSplineMesh with a mesh that has Nanite enabled. The Chaos collisions shown in the Chaos Visual Debu ...

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 ...

The AND node always calculates all inputs

UE - Gameplay - Blueprint - Nov 5, 2015

The AND node always calculates all inputs, even if the first input fails as False. Probably related to [Link Removed] (currently unresolved, but a Select node-specific fix is mentioned in the comme ...

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(). ...