Bug in ULevel::FixupActorFolders.

There is a potential bug in ULevel::FixupActorFolders() in the FixDuplicateFolders section: Suppose you have a folder hierarchy that looks like this:A B(1)B(2) C(1)B(3) C(2) where the letters ...

Add Substrate Material Support to Lumen Performance Overview

UE - Graphics Features - Substrate - Feb 10, 2025

There is a discrepancy when inspecting Substrate materials in the Lumen Performance Overview. Compared to viewing non-Substrate materials the overview show all surfaces in red indicating that Lumen ...

[AI] Navigation System can be constructed in situations where the NavigationObjectRepository subsystem is not valid

UE - AI - Navigation - Feb 7, 2025

Investigate and fix all calls where the Navigation System is constructed without the NavigationObjectRepository subsystem being valid.  ...

[AI] "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" when cooking a project with validation enabled

UE - AI - Navigation - Feb 7, 2025

The cook completes with a warning for "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" which causes many CI pipelines to fail as they use treat warn ...

[Interchange] Crash on asset re-import

UE - Editor - Content Pipeline - Import and Export - Feb 7, 2025

We've started seeing a crash in editor when re-importing one of our assets. <pre class="ql-syntax">Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 783] Array index out of ...

[AI] Navmesh tiles on different layers get removed while streaming out in WP Dynamic Modifiers Only navmesh

UE - AI - Navigation - Feb 6, 2025

 Streaming out the navmesh and streaming the area back into the world before the GC runs causes the navmesh streamed back into the world to only have navmesh tiles on a layer with tiles that would b ...

(GAS) Block tags are ignored in version 5.5.2 if two abilities share the same parent tags structure.

UE - Gameplay - Gameplay Ability System - Feb 5, 2025

Block tags are not working correctly in version 5.5.2, it was working in 5.5.1. This is caused by a change done in version 5.5.2. The exact CL is: CL 35930696 ...

Fixup of spawnables from 5.4 to 5.5 loses custom track names

UE - Anim - Sequencer - Feb 5, 2025

In the process of upgrading from 5.4 to 5.5. One of our systems relies on the internal track names in the sequence to dynamically find an actor to bind the track to. As I was testing the system in ...

Editor/Game Ensure hit with RayTracing enabled on AMD GPU

UE - Graphics Features - Ray Tracing - Feb 4, 2025

A Static Mesh asset will trigger an ensure when generating building the ray tracing acceleration structure on AMD GPUs. ...

Building Geometry Stops UTickableWorldSubsystem Ticking

UE - Gameplay - Jan 31, 2025

Can be mitigated by reopening the Level. There is a repro project provided by the licensee on the case ticket. ...