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. ...

The ChaosCacheManager changes the bSimulatePhysics flag from the ObservedComponents and, if deleted, the change will persist, what can lead to confusion as observed physical entities will inadvertently stop simulating physics

UE - Simulation - Physics - Nov 26, 2024

The ChaosCacheManager (CCM) changes the bSimulatePhysics flag from the ObservedComponents and, if deleted, the change will persist, what can lead to confusion as observed physical entities will inad ...

[CrashReport] Linux crash - error VK_ERROR_EXTENSION_NOT_PRESENT

UE - Platform - Linux - Oct 27, 2017

This is an early trending Linux crash in 4.18, but also occurred in 4.17. It seems to occur before a project loads. Callstack from Log[2017.10.26-01.39.08:606][ 0]LogVulkanRHI: Display: - Found g ...

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 ...

Error: FAsyncPackage::LoadImports for <some asset>: Skipping import PaperTileMap /Script/Paper2D.Default__PaperTileMapActor:RenderComponent.PaperTileMap_0, depends on missing native class

UE - Gameplay - Blueprint Compiler - Jun 30, 2020

User reporting seeing this error start appearing in 4.25.1 (possibly 4.25.x, unsure if they were previously testing on 4.25.0 or not). It appears 'benign' as the expected data still gets loaded, bu ...