Renaming a level by WorldPartitionRenameDuplicateBuilder fails if the level contains GroupActor with non-spatial actors

UE - World Creation - Worldbuilding Tools - World Partition - Oct 24, 2023

Referece to the source level should be fixed by FReplaceObjectRefsArchive, but it is not working because ArIsModifyingWeakAndStrongReferences is not set. It can be fixed by setting the flag.class FR ...

Collision build of LiDAR point cloud assets at runtime does not apply

UE - Editor - Content Pipeline - Datasmith - Oct 24, 2023

Collision build at runtime for LiDAR point cloud does not apply. This applies to Editor and Standalone. If you do not allow collision builds at runtime, this module should not be available at runtim ...

Non-existing config file loading could cause memory leak

UE - Foundation - Core - Oct 19, 2023

The cause of this problem is the Engine has code paths which register a new allocated object to Map without deleting the previous object. In the repro project, whenever hitting Space Bar, the level ...

PIE crash on infinite loop in a BP construction script

UE - Gameplay - Blueprint Runtime - Oct 19, 2023

From the [Link Removed]: We had an issue where PIE was being stopped due to an "infinite loop" being detected in one of the blueprints construction script. This was also crashing the editor as the ...

A disabled Niagara component is respawned unexpectedly by scalability system in some edge cases

UE - Niagara - Scalability - Oct 17, 2023

Even after manually Deactivating a Niagara component, this Niagara component may be revived under certain conditions. This issue occurs when the following conditions are met before the Deactivated N ...

Unable to affect setting cubemap blend in skyLight and reflections on transluscent materials

UE - Rendering Architecture - Oct 17, 2023

Attempting to blend SkyLight Cubemaps via the SetCubemapBlend function to blend between different Cubemaps to make the changes seamless is not reflected. As a workaround, in LumenTracingCommon.ush, ...

Using the end of the curve as a weighted tangent does not yield the expected value.

UE - Anim - Runtime - Oct 16, 2023

When changing the tangent value, the last value is sometimes not 1.0 [Reproduce sample project] [Link Removed] ...

Montage Editor calls NotifyEnds of AnimNotifyState even when paused

UE - Anim - Gameplay - Oct 13, 2023

In 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 ...

Compiling Blueprints breaks socketed attachments of actors attached to non-root components

UE - Gameplay - Blueprint - Oct 12, 2023

When blueprints are compiled, instances of those blueprints have their attachments detached and then reattached. Reattachments always occur on the RootComponent regardless of which component they we ...

Hitting a breakpoint in widget blueprint while running PIE with Selected Viewport mode blocks entire editor rendering

UE - Editor - UI Systems - UMG - Oct 6, 2023

This problem does not occur when running PIE with New Editor Window mode. ...