Children of editor-only actors do not maintain correct transforms when placed inside level instances for PIE and cooked builds

UE - World Creation - Worldbuilding Tools - Level Instances - Oct 20, 2025

We have found an issue where children of editor-only actors get wrong transforms in PIE and cooked builds when placed inside level instances. This affects both engine version 5.5 and 5.6. The issue ...

In the GameUserSettings class, Landscape quality is not taken into account by GetOverallScalabilityLevel, but is changed by SetOverallScalabilityLevel.

UE - Gameplay - Oct 17, 2025

Context: GameUserSettings stores user settings for a game, for example graphics and sound settings. The Scalability settings provide a way for to adjust the quality of various features in order to m ...

GeneSplicerModule has linking errors in a Development target

MetaHuman - Oct 16, 2025

The FArchiveMemoryStream class is defined in GeneSplicerModule and RigLogicModule. This generate linker error as this doesn't respect the "One Definition Rule"  1>Module.GeneSplicerModule.cpp.ob ...

Mutable - morph does not work for a skinned mesh with more than one uv channel

UE - Anim - Mutable - Oct 16, 2025

The morph functionality fails to change when the skinned mesh contains more than one UV channel in a Customizable Object. ...

[Interchange] FBX - Front Facing X-Axis and Flipped Bone Orientation During Animation

UE - Anim - Runtime - Oct 15, 2025

Actors attached to a skeleton imported through a FBX file with the Front Facing X-Axis option enabled are flipped when the skeleton is animated. ...

Intermittent Content is Missing from Cook errors for objects with Niagara packages

UE - Niagara - Oct 15, 2025

Intermittently when cooking large licensee projects, an error is reported at the end of the cook:LogCook: Error: Content is missing from cook. Source package referenced an object in target package b ...

Light Leak Issue in Modular Buildings (Lumen HZBTraversal)

UE - Graphics Features - Lumen - Oct 14, 2025

Starting in Unreal Engine 5.6, disabling "r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal" can lead to light leaking between adjacent or overlapping meshes. Also tested on Release-5.6, CL: 4523 ...

Smart Link inactive by default when NavLink is a ChildActor

UE - AI - Navigation - Oct 14, 2025

When placing a NavLinkProxy in ChildActor, the link is not enabled by default. In this situation, setting SetSmartLinkEnabled to true does not establish the connection. You must first set it to fal ...

Lightmass CalculatePointShadowing regression in UE5.6

UE - Graphics Features - Oct 14, 2025

There is a regression or change in the Build Lighting process when using Lightmass in Unreal Engine 5.6:When building lighting with Lightmass calling the CalculatePointShadowing function, the result ...

Spline mesh deform breaks WPO when used with Nanite meshes

UE - Graphics Features - Nanite - Oct 13, 2025

Nanite spline meshes deforming along the world normal vector do not use the same world normal as a non-Nanite spline mesh. This results in inconsistent behavior between Nanite and non-Nanite spline ...