Unreal Engine Issues
Unreal Engine Issues
Skeletal mesh LODs never stream up under SSAM: FSkeletalMeshSceneProxy caches ForceStreamedLOD and is never re-gathered
UE - World Creation - Worldbuilding Tools - Jul 29, 2026UE 5.8, cooked build, SSAM enabled (s.StreamableAssets.UseSimpleStreamableAssetManager=1, required by FastGeo). Symptom: characters spawn at a crude LOD and can never stream up for the lifetime of ...
ApplicationReceivedScreenOrientationChangedNotificationDelegate does NOT work properly on Android
UE - Platform - Mobile - Aug 5, 2019ApplicationReceivedScreenOrientationChangedNotificationDelegate supports iOS but not Android. Probably, Java_com_epicgames_ue4_GameActivity_nativeOnConfigurationChanged should be useful for fix thi ...
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 ...
StreamingGeneration: Actor desc mutator phase now writes ActorDescView directly, breaking the cluster-invariant check in ValidateContainerInstanceDescriptors
UE - Engine Scaling - Streaming - World Partition - May 22, 2026This report is from an EPS case: We hit a regression upgrading our project from 5.7 to 5.8. Map Check (and any other path that ends up calling UWorldPartition::CheckForErrors) assert inside FWorld ...
Spot Light USD Export Produces Incorrect Intensity Values Based on Cone Angle and Source Radius
UE - Editor - Content Pipeline - USD - 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 ...
Reset to default behavior for arrays is inconsistent about updating customized struct headers
UE - Editor - Verse Class Editor - Jun 22, 2023The behavior for resetting the default for customized struct properties is inconsistent and needs to be reviewed and fixed. Currently we see this behavior:In non-array properties, the header will be ...
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. ...
MotionWarping does not recognize new MontageInstance with the same montage
UE - Characters - 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 ...
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. ...