Lumen reflections break when the normals don't match the pixel depth information.

UE - Graphics Features - Lumen - Oct 23, 2025

Lumen Reflections can leave black spots in chrome materials with strong normals. Also tested on UE 5.5, CL: 41545209 and UE 5.6, CL: 45232827 ...

Static Mesh imported from USD file has empty UV channel

UE - Editor - Content Pipeline - Import and Export - Oct 6, 2020

When importing static mesh from USD file then it has the wrong amount of UV channels. Selecting a UV channel shows an empty area in the viewport. Regression: YES - not reproduced in 4.25.3 produc ...

Lumen Reflections in Stereo are broken after Nvidia GPU Driver Update

UE - Platform - XR - Jul 29, 2024

After updating the NVidia graphics driver to v.552.74+, reflective/mirror materials appear broken and render with black and white lines in VR mode if they are in a level with a Post Process Volume w ...

Cross-Compiling for Linux-ARM fails to compile

Tools - Aug 11, 2015

Following the directions on the wiki for cross compiling on Linux ([Link Removed]) fails when trying to package the project. ...

Event not saved correctly when duplicating Level Sequence

UE - Anim - Sequencer - Nov 21, 2019

This issue is similar to [Link Removed]. But I tested the shelve 10164190 mentioned in the comments. It didn't work. ...

Ensure condition failed : Unprocessed LatentActions accumulate by SetPlaybackPostion using Play method

UE - Anim - Sequencer - Nov 9, 2021

If some sequencer events are added to LatentAction queue while calling SetPlaybackPostion using Play method, the events will not be digested. So the LatentActions cause that ensure condition failed ...

Local Exposure can cause large variations in PreExposure under certain conditions

UE - Graphics Features - Sep 16, 2025

PreExposure is influenced by LocalExposure in PostProcessEyeAdaptation.cpp:1265. It appears when the scene is particularly dark and using manual exposure, the LastAverageLocalExposure can read a lar ...

Lighting Channels Do Not Function with 78+ Lights on Actor

UE - Graphics Features - Oct 20, 2017

Lighting channels do not function when the number of lights affecting actors is 79 or higher. Any number of lights that is 78 or fewer will honor lighting channel assignments. ...

BP - Class default value is temporary reset after parent c++ class compile.

UE - Foundation - Cpp Tools - Hot Reload - Nov 21, 2017

class default value after c++ class compile will temporary initialized. It will be restored when opening the project again. ...