ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision

UE - Simulation - Physics - Jan 27, 2025

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...

Inconsistent ListView entry sizes can prevent the ListView from being scrolled to the bottom

UE - Editor - UI Systems - Slate - May 4, 2022

Since the contents of a ListView are virtualized, the ListView estimates the size of the scroll box's contents based on the on-screen elements. This can lead to some situations where DistanceFromBot ...

Composite font uses a sub-font, even when the sub-font doesn't support the character

Tools - Apr 7, 2016

I have a fix for this shelved in CL# 2937344, so it would be good to get it into 4.12 once the user verifies the fix. ...

MotionWarping does not recognize new MontageInstance with the same montage

UE - Anim - Gameplay - Jan 11, 2023

When the same AnimMonotage is played again while moving with MotionWarping & RootMotion, UAnimNotifyState_MotionWarping does not recognize it. From licensee: The issue was that in URootMotionMod ...

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. ...

[CrashReport] Mac crash - libobjc.A.dylib!objc_retain() [UnknownFile]

UE - Platform - Apple - Nov 10, 2017

This is a longstanding but low frequency Mac crash. User DescriptionsChanging camera shake values and testing in a new editor window Callstack from Log[2017.11.09-19.23.22:392][ 63]LogMaterial: Mi ...

[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 ...

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. ...

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. ...

COTF has issues with out-of-source projects

It is expected that cooking, including COTF, will fix-up all string asset references. There were a few reasons this wasn't happening, but we should get these fixes into 4.15 as the impact was worst ...