LevelEditor: "Replace Actor" marks level as dirty even when using external actors

UE - World Creation - Worldbuilding Tools - Jul 15, 2024

When using external actors, adding/removing/replacing/editing an actor instance inside a level does not cause any modification to the Level package, which helps reduce contention for the map file on ...

[CrashReport] UE4Editor_Slate!TAttribute<FText>::Get() [attribute.h:130]

UE - Editor - UI Systems - Slate - Jul 13, 2017

This is a common crash affecting users in 4.16 User DescriptionsI imported an FBX and the editor crashed.alembic import from brekelwhats wrong with the ue4 alembic importer? Source Context 120 ...

FMovieSceneSkeletalAnimationParams::MapTimeToAnimation returns the wrong value if InFrameRate is not the Tick Resolution

UE - Anim - Sequencer - Jan 16, 2026

FMovieSceneSkeletalAnimationParams::MapTimeToAnimation takes in an FFrameTime and FFrameRate and is supposed to tell you which frame of animation that evaluates to, when accounting for looping, play ...

[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]

UE - Rendering - Architecture - RHI - May 29, 2026

#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...

[CrashReport] UE4Editor_SlateCore!FHittestGrid::GetBubblePath() [hittestgrid.cpp:145]

UE - Editor - UI Systems - Slate - Oct 27, 2017

This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Based on the affected project names, this crash seems co ...

uexp file of certain maps are always packaged when patching

UE - Foundation - Core - Nov 17, 2017

When generating a patch, (patch pak file) the .uexp file of the Editor Start Map and the Game Default Map are both packaged into the patch, even if another map is specified. Example: Editor Start ...

Orientation Warping breaks incoming poses where bones are in component space

UE - Anim - Gameplay - Apr 17, 2025

The orientation warping node breaks incoming poses where bones are already in component space. This is because, in EvaluateSkeletalControl_AnyThread, we are repeatedly setting bone transforms direc ...

[CrashReport] Access violation - FLandscapeEditDataInterface::SetAlphaData()

UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017

This is a common crash affecting users in 4.15 and 4.16. This callstack was previously linked to [Link Removed], but that had a specific repro case that was fixed in 4.14. Users are not providing ...

[CrashReport] Crash related to refreshing Destructible Mesh - SaveExistingSkelMeshData()

UE - Simulation - Physics - Destruction - Jul 20, 2017

This is a common crash affecting users in 4.16. User DescriptionsPressing the button to restart the basic mesh in the destruction editor causes the crash.Refreshing a Destructible Mesh that has had ...