Unreal Engine Issues
Unreal Engine Issues
No arm64 folder exists in plugins leading to an Error when packaging plugins
UE - CoreTech - Nov 16, 2022Regression: Checked in UE5/Release-5.0, the folder is missing from the plugin as well. This issue appears to be a problem with packaging the plugin itself, rather than packaging a full project. Pac ...
NaN Present on IOS after UE5.6 Because of Removal of MobileSpecularGGX
UE - Platform - Mobile - Sep 24, 2025In UE5.6 MobileSpecularGGX was removed and now mobile devices also run D_GGX. The problem is that there are still cases where very bright values are produced (image 1) and thus NaNs appear in the Bl ...
LevelEditor: "Replace Actor" marks level as dirty even when using external actors
UE - World Creation - Worldbuilding Tools - Jul 15, 2024When 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 ...
Orientation Warping breaks incoming poses where bones are in component space
UE - Anim - Gameplay - Apr 17, 2025The 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 ...
Root motion from montages does not get mirrored correctly
UE - Anim - Gameplay - Dec 2, 2022A customer noticed that root motion did not mirror properly when using montages. The issue is that the root motion mirroring code is only called from FAnimSync::TickAssetPlayerInstances . Th ...
Unexpected corrections when sliding against other characters
UE - Gameplay - Player Movement - Oct 19, 2023We are seeing unexpected movement corrections sometimes when pushing one player character up against another character that isn't moving, or against other static primitives that have round features ...
FTickTaskLevel::RescheduleForIntervalParallel Crash
UE - World Creation - Worldbuilding Tools - Oct 11, 2023Short description from Licensee (attached UDN has more info):When streaming a level in and/or out (out especially in World Partition due to the bRequireFullVisibilityToRender variable usage) there i ...
Montage Editor calls NotifyEnds of AnimNotifyState even when paused
UE - Anim - Gameplay - Oct 13, 2023In the Animation Montage Editor, NotifyEnd is unexpectedly called when a time marker is in the middle of an AnimNotifyState and the animation preview gets paused. Because the Animation Montage Edito ...
Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity
UE - Graphics Features - Nov 27, 2025Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...
Body Setup of a Static Mesh with Simple Collision will pass validation, but removing it and using only a Complex collision and setting Collision Complexity "Use Complex as Simple" will fail validation: "Bone None requires at least one collision shape".
UE - Simulation - Gameplay - Oct 20, 2025Context: By default, Unreal Engine creates both simple and complex shapes, then, based on what the user wants (complex query versus simple query), the physics solver will use the corresponding shape ...