Lighting data wiped if sub level is hidden while rebuilding lighting for visible levels

UE - Graphics Features - Jan 11, 2017

When building lighting now you can no longer have a hidden sub level and have it retain it's built light if it was previously built. For instance, if you have a persistent level and hide the sub-lev ...

Sub Surface Shading Model has Strange Blotch Color Artifacts when Used with a Ambient Cubemap

UE - Graphics Features - Sep 23, 2019

Sub surface shading model has strange blotch color artifacts when used with ambient cubemap. Since the subsurface profile shading model can't be used with ambient cubemap I wanted to use the regular ...

CheckCompilingPSOs assert in FMaterialPSORequestManager::MarkCompilationComplete fires occasionally

UE - Rendering - Architecture - RHI - May 17, 2025

Find the root cause and fix it. Potential issue based on logs:New RequestA is created in PrecachePSOs and its collection task is dispatched and finishedRequestA is waiting for compilation taskReque ...

Geometry in sublevel created with "Load Level Instance" ignores level transform

UE - LD & Modeling - Modeling Tools - BSP - Sep 26, 2017

Geometry in sublevel created with "Load Level Instance" ignores level transform. Other objects, such as Static meshes are affected by the transform. This issue is not a regression. Versions tested: ...

UClass::SparseClassDataStruct null at editor-time for child blueprints until compile

UE - Framework - Blueprint - May 29, 2024

Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...

[CrashReport] Linux_PlatformCreateDummyGLWindow()

UE - Platform - Linux - Nov 16, 2017

This is a trending Linux crash in the 4.18 release Callstack from Log[2017.11.10-14.42.41:021][ 0]LogLinux: Error: appError called: Assertion failed: [File:/media/***/OS/UnrealEngine-release/Engi ...

[CrashReport] UE4Editor-Slate.dylib!FMenuStack::PostPush(TSharedPtr<IMenu, (ESPMode)0>, TSharedRef<FMenuBase,()

Tools - Dec 1, 2017

This is a longstanding but infrequent Mac crash that has occurred since at least 4.15. Users have not provided any descriptions. Callstack from Log[2017.11.19-04.18.41:283][ 0]LogSlate: Took 0.000 ...

[Feature Request] CVars for HISMC

UE - World Creation - Worldbuilding Tools - Foliage - Jun 18, 2021

Currently some (if not all or most) foliage CVars affect both foliage and HISMC. It would be nice to split this so that users can change the values of one without affecting the other. ...

DestructibleMesh does not correctly effect vertex color of material.

UE - Simulation - Physics - Destruction - Oct 10, 2017

Destructible Mesh does not correctly affect vertex color. ...

Selected item in property matrix cannot be deselected

Tools - Aug 23, 2016

When selecting an item in the Property Matrix you cannot deselect. This affects changes you make that are supposed to be across all items selected by making them only affect the item selected. ...