Content is Missing from Cook and indeterminism: StaticMeshComponents in Blueprints that copy data into themselves from StaticMesh have indeterminism due to StaticMesh not yet finished loading, postloading, or building

UE - Foundation - Nov 12, 2025

Content is Missing from Cook warnings are warnings reported at the end of cook phase of a project's data build. They report that data used by a cooked package will not be available at runtime. This ...

LevelInstance Property overrides: Niagara properties cannot be overriden

UE - World Creation - Worldbuilding Tools - Level Instances - Nov 10, 2025

LevelInstance Property overrides are broken when duplicating a LI

UE - World Creation - Worldbuilding Tools - Level Instances - Nov 10, 2025

Upon light debugging, it seems like the overrides depend on the name of the actors in the LI. The duplicated LI does have FLevelInstanceActorPropertyOverride but the Actor names were not updated upd ...

Build crash when enabling r.CreateShadersOnLoad=1

UE - Rendering Architecture - Shaders - Nov 10, 2025

When "r.CreateShadersOnLoad" is enabled, cooking will crash due to failure to create a shader. This occurs on //UE5/Release-5.5, CL: 41545209 and //UE5/Release-5.6, CL: 45232827 ...

WorldPartitionConvertCommandlet hits an assert when converting a persistent level that contains a sub-level with a landscape

UE - World Creation - Worldbuilding Tools - Nov 7, 2025

Context: The Window tab allows a user to open the Levels window in order to add a sub-level to a persistent level. For Unreal Engine 5.0 and beyond, World Partition has made the Levels window obsole ...

5.6 Skeletal Meshes with Disabled Sections Flicker in Ray Tracing Scene

UE - Graphics Features - Ray Tracing - Nov 7, 2025

Skeletal meshes with disabled mesh sections will flicker in the Hardware Ray Tracing Scene. Also tested on //UE/Release-5.6, CL:45232827 ...

Adding a streamed empty LevelInstance in a WP level will result in an incorrect mapcheck error

UE - World Creation - Worldbuilding Tools - Level Instances - Nov 7, 2025

This is an edge case that can also be caused when a Level only contains actors were `SupportsExternalPackaging` is false.  This is likely the case for the "empty" level which surely contains a Level ...

Animation Constraint Jitter in Sequence when Constraining Layered Control Rig node

UE - Anim - Anim in Engine - Nov 6, 2025

When using constraints with layered control rigs, you get jitter on the constrained object. ...

Rotator visual helper appears in local Presentation exports

TM - Tools - Nov 6, 2025

Reported in SF [Link Removed] The Rotator animator's visual helpers will be visible in locally exported Presentations when it should be hidden. This does not affect the Translator animator. ...