Spot Light USD Export Produces Incorrect Intensity Values Based on Cone Angle and Source Radius

UE - Editor - Content Pipeline - USD - Apr 3, 2026

UPDATE: Should be fixed as of CL#52537078 (fb7af1) USD: Bake all frames of exposure animation tracks. When exporting Unreal Engine spot lights from a level to USD, lights with identical EV intensit ...

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] Linux crash - TOpenGLBuffer<FOpenGLBaseVertexBuffer, 34962u, &()

UE - Platform - Linux - Sep 14, 2017

This is an infrequent Linux crash that has affected a few users in 4.17.1 Callstack from Log[2017.09.12-17.23.41:651][ 0]LogRHI: OpenGL MajorVersion = 4, MinorVersion = 5, ShaderPlatform = GLSL_43 ...

ARSharedWorld, AREnvProbe, and ARSaveLoad fail to build for iOS with clang error

UE - Platform - Mobile - Jul 18, 2019

ARSharedWorld fails to package at the build command for iOS with the following messages. Packaging (iOS): [1/4] sh /Volumes/Storage/Workspaces/Release/Samples/AR/ARSharedWorld4.23/Binaries/IOS/ARS ...

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 ...

Xcode 26/16.4 Metal Toolchain generates metallib's that are not compatible with iOS 16

UE - Platform - Apple - Sep 23, 2025

Below is the error output from FirstPerson template as a C++ project: {+}../../../FirstPerson58CPP/Content/firstperson58cpp_sf_metal_es3_1_ios-metal_es3_1_ios.0.metallib, 5881486 bytes!2025-09-23 1 ...

[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 ...