PakFiles: Unmounting PakFile while requests are still in progress causes assertion failure in UnMount

UE - Foundation - Mar 31, 2022

[Link Removed] Licensee is using the chunk downloader. On Shutdown method of their GameInstance, they call FChunkDownloader->Finalize. When they quit the game (Alt+F4) during a chunck download an a ...

Dragging a BP variable into a category can produce inconsistent results

UE - Gameplay - Blueprint Editor - Jan 18, 2019

The drag-onto-category operation is assigning the prettified category name, not the actual category name, resulting in variables that are not actually in the same category, even though they appear t ...

Custom Primitive Data on BP instance not taking affect while in editor

UE - Rendering - Architecture - Apr 5, 2023

Original Repo is from 4.27, however, it still happens in 5.2. This is happening because the Instance Data system does not update the field UPrimitiveComponent::CustomPrimitiveDataInternal from the d ...

Nanite meshes are lit differently in Actor Colorization view modes than non-Nanite meshes

UE - Graphics Features - Nanite - Aug 28, 2024

When the Lit > Actor Coloration > Affects Navmesh or other Actor Coloration mode is used, Nanite meshes apply lighting differently than non-Nanite meshes which can make it difficult to use the Actor ...

[Enhanced Input] Edge case where bShouldBeIgnored incorrectly being reset after FlushPressedKeys is called

UE - Gameplay - Input - Apr 2, 2026

[Link Removed] From UDN, the steps for their repro case: Normal case: Frame N : AddMappingContext → bShouldBeIgnored=true → FlushPressedKeys → bDown=false Frame N+1: OS IE_Repeat arrives → ...

BuildPatchTool crashes on Mac and Linux when building android or ios with multiple chunks

Portal - Feb 18, 2020

"It seems that deallocation of TLazySingleton<FInternationalization> causes unhandled exception. If DISABLE_LAZY_SINGLETON_DESTRUCTION=1 is provided - the build completes successfully" ...

Capsule Shadows Not Visible When Using Movable Skylight With Bright Lower Hemisphere Color and Indirect Lighting Cache

UE - Graphics Features - May 9, 2018

I have managed to reproduce this issue in 4.18.3 and 4.19.2. In order to make the Capsule Shadow disappear:Indirect Lighting Cache must be used (Volumetric Lightmap works)Skylight must be set to 'M ...

Packaging to HTML5 fails when Online Framework is enabled

UE - Online - Nov 17, 2018

Packaging a project to HTML5 while Online Framework is enabled seems to cause packaging failures. It produces the following errors from the Output Log:   PackagingResults: Error: unresolved symbol: ...

GetPackageLengthForCooking can be much larger than the actual file path length

Tools - Jul 10, 2019

If the file path with the asset contains a project name, the cooking file pathlength is incorrectly increased. The following code in ContentBrowserUtils :: GetPackageLengthForCooking causes this is ...

Access Violation - UMovieSceneFolder::PostLoad - Accessing freed memory

UE - Anim - Sequencer - Sep 19, 2024

A licensee has hit an access violation issue due to a movie scene containing a reference to an invalid child object binding. It triggers in the following method: UMovieSceneFolder::PostLoad // Vali ...