WorldPartitionActorDescs for LevelInstanceActors are broken when migrating world partitioned level

UE - World Creation - Worldbuilding Tools - Level Instances - Jun 13, 2023

WorldPartionActorDescs will be restored to the correct properties when resaved. They can also be fixed by the WorldPartitionResaveActorsBuilder commandlet. ...

Compile failure packaging for Linux in arm-unknown-linux-gnueabihf from Windows

Tools - Apr 20, 2017

Packaging for Linux is failing when setting the TargetArchitecture=ArmUnknownLinuxGnueabihf in the DefaultEngine.iniUATHelper: Packaging (Linux): UnrealBuildTool: C:\LinuxXC_ToolChain\v9_clang-4.0.0 ...

BoneList and BoneFilterActionOption in LOD0 of LODSettings are displayed after editing other LOD level

UE - Runtime - Animation - Jul 31, 2023

BoneList and BoneFilterActionOption in LOD0 of LODSettings are filters by the following code. void FSkeletalMeshLODSettingsDetails::CustomizeDetails(IDetailLayoutBuilder& LayoutBuilder) { ... st ...

Missing PSO Precaches in the engine

UE - Rendering - Architecture - RHI - Aug 20, 2025

A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...

FMath::Eval ignores groupings while solving

UE - Core - Systems - Nov 8, 2022

This is not a regression. Tested in //UE5/Release-5.0 CL20979098 FMath::Eval ignores groupings while solving problems. This has caused some confusion with users who are expecting the groupings to b ...

Translucent meshes randomly flicker when using VSM

UE - Rendering - Features - Jun 23, 2026

Flickering can occur on translucent materials, usually in the distance when there is at least one directional light and when using VSM. Flickering seems highly dependent on framerate and timing. L ...

[CrashReport] rml::internal::Block::findObjectSize() - UBlueprintGeneratedClass::DestroyPersistentUberGraphFrame

UE - Gameplay - Blueprint - Sep 7, 2017

This is an infrequent crash that has occurred for a few users exclusively in 4.17.1 (possible regression from 4.17.0?). Users have not provided any descriptions of their actions when the crash occu ...

Crash when playing HLS video with ElectraPlayer on iOS16

UE - Media Framework - Mar 15, 2023

Licensee reported crash when playing HLS video with ElectraPlayer on iOS16. According to their research, we can avoid the fix by doing the following: Delete check() in the corresponding line Engine ...

[CrashReport] UE4Editor_Engine!UModelComponent::CommitSurfaces() [modelcomponent.cpp:163]

UE - LD & Modeling - Modeling Tools - BSP - Oct 26, 2017

This is a somewhat common crash that has existed since at least 4.14.. It appears related to an Undo operation on geometry. User DescriptionsUndoing a move of a boxbrush wall and staircaseundoing i ...

Compile error during build stage when packaging for tvOS

UE - Platform - Mobile - Dec 9, 2016

Compile error packaging for tvOS: Does not affect iOSUATHelper: Packaging (tvOS): UnrealBuildTool: D:\Build\joseph.wysosky_Main\Engine\Source\Runtime\Core\Private\iOS\IOSAppDelegate.cpp(388,12): ...