Premature prompt with failed import when Importing LOD Level for Skeletal Mesh

UE - Editor - Content Pipeline - Import and Export - Apr 7, 2016

When importing a LOD Level for Skeletal Meshes, the user is greeted with a windows directory window and a message that states "Failed to import mesh for LOD level 1" As the user states, this is a s ...

SkyLight Leaking does not affect reflections when the SkyLight is static but static lighting is disallowed

UE - Graphics Features - Sep 10, 2025

Reflections do not receive SkyLight leakage contribution from a static SkyLight when static lighting is disallowed. This is caused by the function UpdateSkyIrradianceGpuBuffer checking if the SkyLig ...

NaN Present on IOS after UE5.6 Because of Removal of MobileSpecularGGX

UE - Platform - Mobile - Sep 24, 2025

In UE5.6 MobileSpecularGGX was removed and now mobile devices also run D_GGX. The problem is that there are still cases where very bright values are produced (image 1) and thus NaNs appear in the Bl ...

Block noise on particles/skeletal meshes when launched onto certain Android devices

UE - Platform - Mobile - Oct 12, 2016

When launching particles and skeletal meshes on certain devices, they create block noise pixels instead of a smooth flame for example. Regression: Yes Did not occur: Binary 4.12.5-3039270+++UE4+Rel ...

"Allow Custom Depth Writes" Creates Artifacts In Depth Buffer

UE - Graphics Features - Jan 5, 2017

When a transparent material has "Allow Custom Depth Writes" enabled it is prone to have artifacts in the custom depth buffer under specific conditions. The conditions are as follows:The translucent ...

VSCode finds intellisense errors in Project source files: cannot open source file "UBT_COMPILED_PLATFORM/UBT_COMPILED_PLATFORMPlatformCompilerPreSetup.h"

UE - Foundation - Cpp Tools - Jan 28, 2020

VSCode finds intellisense errors in Project source files: cannot open source file "UBT_COMPILED_PLATFORM/UBT_COMPILED_PLATFORMPlatformCompilerPreSetup.h" Similar to [Link Removed], but that was onl ...

SWorldPartitionEditorGrid2D causing editor to crash

UE - World Creation - Worldbuilding Tools - World Partition - Mar 13, 2023

Previewing Node in Material Editor Produces Unexpected Output with DX12

UE - Graphics Features - May 16, 2018

Per Licensee: Since we switched to DX12 we started to see strange behavior in material previews. I was able to reproduce the problem in UE 4.19 vanilla as well. We usually have to force recompilin ...

[Quartz] - The multiplier does not always respected on the Quartz Quantization Boundary

UE - Audio - Quartz - May 13, 2022

Increasing the multiplier past a certain point causes sounds on a Quantization Boundary to struggle to play at the correct time. The repro above uses 1/32, but this also repros with other values. ...

Steam friends list is duplicated when opened for a second time in the packaged version of Shooter Game

UE - Networking - Jun 29, 2015

If a user is logged into a Steam account with between 1 and ~10 friends (Max depends on resolution, as it'll push the excess off the screen) and they open the friends list multiple times, it'll dupl ...