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 ...

Landscape Splines in Partially Loaded World Partition Levels Can Cause Nanite Landscape Invalidation

UE - Graphics Tools - Terrain - Nov 7, 2025

Certain placements of landscape splines in world partition levels can cause Nanite landscape proxies to invalidate, and switch back to their non-nanite version. This happens when specific regions of ...

Sequencer Crash when Hovering over Binding Properties on a Component with Spaces in its Name

UE - Anim - Sequencer - Nov 7, 2025

Crash when binding to new components that have spaces in their name and you attempt to access their bindings. ...

Outliner eye toggle fails to hide static meshes when Affect Indirect Lighting While Hidden is enabled

UE - Rendering Architecture - Nov 5, 2025

When a static mesh has the property Affect Indirect Lighting While Hidden enabled, toggling its visibility via the Outliner eye icon does not hide the mesh in the editor viewport. The actor remains ...

Crash when compiling Blueprint Function containing a connected Set Variable node for a local variable named after a replicated Actor property

UE - Framework - Blueprint - Nov 5, 2025

Creating a local variable inside a Blueprint Function with the same name as a replicated property of AActor (for example, “Role” or “RemoteRole”) and then using a connected Set Variable node for it ...

GAS: FActiveGameplayCueContainer::RemoveCue crash while iterating removals when consecutive Cue tags are conditionally added and the conditional effects removed in ascending order

UE - Gameplay - Gameplay Ability System - Nov 4, 2025

When removing gameplay effects by tag, if the tag that is being removed has other tags that are dependent on it in a cyclical way an "array out of bounds ' error can be triggered. ...

Deadlock in UAnimationSequencerDataModel::Evaluate where FScopeLock Lock(&EvaluationLock) blocks execution indefinitely

UE - Anim - Nov 4, 2025

When both the Sequencer Editor and an Animation Curve Editor are open for the same animation asset, the editor freezes completely upon editing the curve. Analysis indicates that the freeze is caus ...

UMG: RetainerBox with zero-size child returns incorrect LayerId on OnPaint()

UE - Editor - UI Systems - Nov 4, 2025

When a RetainerBox contains a child that for some reason has a desired size of zero, its OnPaint() method can incorrectly return LayerId 0. Afterwards, widgets further down the hierarchy can base th ...

Client Gameplay Effect stuck on due to duplicate ReplicationIDs

UE - Gameplay - Gameplay Ability System - Oct 31, 2025

We've been tracking down a problem recently with the Gameplay Ability System where a gameplay effect is properly removed on the server, but the client has the gameplay effect stuck on permanently. ...

[PCG] Undoing the deletion of a pcg actor removes the Instance Category from the pcg component, specifically no graph parameter can be seen.

UE - World Creation - Procedural Tools - PCG Component - Oct 31, 2025

Context: PCGComponents on actors contains a category "Instance" that allows the user to connect a PCG Graph of their choosing to the PCGComponent which allows the Procedural Node Graph to sample the ...