Unreal Engine Issues
Unreal Engine Issues
ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision
UE - Runtime - Simulation - Jan 27, 2025ensure(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 ...
Spot Light USD Export Produces Incorrect Intensity Values Based on Cone Angle and Source Radius
zComponent - Archive - Apr 3, 2026UPDATE: 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 ...
Crash Occurs When Attempting to Resume Execution After Hitting a Breakpoint in a BT Task
UE - Gameplay - Oct 6, 2017When a breakpoint is hit in a BT Task, if you attempt to use CTRL+P to search for and open the BT the task is being run in, try to resume execution, and then return to the original BT Task Blueprint ...
Inconsistent ListView entry sizes can prevent the ListView from being scrolled to the bottom
UE - AI Workflows - UI Systems - Slate - May 4, 2022Since 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, 2016I 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. ...
[CrashReport] UE4Editor_CoreUObject!FCompressedChunk::FCompressedChunk()
UE - Foundation - Core - Jul 24, 2017This is a common crash affecting users in 4.16 and the 4.17 Previews. The two descriptions provided by users say their crash occurred after updating their project from 4.13. User DescriptionsUpgra ...
MotionWarping does not recognize new MontageInstance with the same montage
UE - MVF Character - Animation - Jan 11, 2023When 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 ...
[CrashReport] Mac Crash - UE4Editor-Engine.dylib!LoadPhysXModules(bool)::$_0::operator()()
UE - Platform - Apple - Aug 15, 2017This is a trending Mac crash coming out of the 4.17.0 release. It appears to occur before users are able to open their project. I have not found any records of this crash occurring on Windows. Use ...
UAssetManager::ChangeBundleStateForPrimaryAssets: Performance: Avoid canceling loads in progress when new bundles added and the in progress bundles are kept
UE - Core - Data Pipeline - Cooker - Mar 4, 2024UAssetManager::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
zComponent - Archive - Jul 3, 2025Consider 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 ...