UAssetManager::ChangeBundleStateForPrimaryAssets: Performance: Avoid canceling loads in progress when new bundles added and the in progress bundles are kept

UE - Foundation - Data Pipeline - Cooker - Mar 4, 2024

UAssetManager::ChangeBundleStateForPrimaryAssets allows adding new BundleNames to the list of BundleNames loaded for a PrimaryAssetId. Each BundleName specifies a BundleEntry with a list of assets. ...

Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate

UE - Anim - Sequencer - Jul 3, 2025

Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...

[CrashReport] ULevel::GetWorldSettings - UMaterialFunctionThumbnailRenderer::Draw

Tools - Oct 30, 2017

This is a common crash that has occurred since at least 4.16. The callstack is nearly identical to [Link Removed], which appears to be fixed in 4.18; and [Link Removed], which has not. The differen ...

Unknown force is applied to the cloth when changing the skeletal mesh LoD with cloth.

UE - Simulation - Physics - Character - Jul 11, 2019

There are 3 issuesEach particles don't restore its previous position. Which is for calculating velocity by verlet iteration.The previous transform is cleared by current transform. It provides zero v ...

MovieRender Pipeline Skips Output Frames during GC

UE - Anim - Sequencer - Jun 8, 2020

This is being seen in the wild... can release a temporary fix until 4.26 when we can change the headers and fix it for real. ...

Spatialization is inaccurate on iOS/tvOS

UE - Audio - May 9, 2017

Also occurs in 4.16 Tested on iPhone6S+_4982 OS: 10.2.1 and tvOS 10.2 ...

Slight delay when switching between UMG buttons on Mac

UE - Editor - UI Systems - Dec 30, 2014

There is a slight delay when clicking between two different UMG buttons on Mac. Tested on OSX 10.10.1. There also appears to be a flicker on the Menu Bar. ...

Trace collision audio occlusion is not working on iOS/tvOS

UE - Audio - May 9, 2017

The Left side of the test map works in 4.16 and Main so marking this as a regression. Tested on iPhone6S+_4982 OS: 10.2.1 and tvOS 10.2 ...

Reintroduce UE4 Material Layer drag & drop behavior in UE5

UE - Rendering Architecture - Materials - Oct 19, 2023

This behavior has changed from UE4 to UE5 due to a fix to an unrelated bug ([Link Removed]). Reintroduce the old behavior without causing a regression that reintroduces Ben's fixed bug. ...

Aligning comment boxes does not move the nodes within them

UE - Gameplay - Blueprint - Nov 13, 2015

Aligning comment boxes does not move the nodes within them. Reproduced in 4.10.0 binary and Main (CL# 2765781). Not a regression: Blueprint node alignment was not available prior to 4.10. ...