Packed Level Actors will create ISMs with inverted normals when a portion of static meshes have negative scales. This is apparent with two-sided materials.

UE - World Creation - Worldbuilding Tools - Feb 17, 2025

Packed level actors will create ISM instances with inverted normals when the selection of meshes used to create the packed level actor contains a subset of meshes with negative scales. This is the ...

Error in output log when Revision Control submits an asset for deletion with Virtual Assets enabled

UE - CoreTech - VirtualAssets - Feb 17, 2025

With Virtual Assets setup in a project, when an asset is deleted and the changelist then submitted via revision control, the virtualization system will attempt to read the deleted asset. The submit ...

Additives using Frame From This Animation as the Base Pose Type fail to retarget correctly

UE - Anim - Rigging - Retargeting - Feb 13, 2025

Additive animations that use a frame from their own sequence as a base pose are initially broken when retargeted.  Users have to refresh the properties that select the base pose in order to fix the ...

5.4, FRHIMemoryPool leaks memory

UE - Rendering Architecture - RHI - Feb 12, 2025

FRHIMemoryPool will leak data when it is destroyed. "FRHIMemoryPool::Init()" will create "FRHIMemoryPool::DesiredAllocationPoolSize" new "FRHIPoolAllocationData" objects, stored in "FRHIMemoryPool: ...

Iris - incorrect initial state in pawn's BeginPlay if replicated via huge object path

UE - Networking - Iris - Feb 11, 2025

This occurs when the pawn is initially replicated using the huge object path when first connecting to a server. Destroying and restarting the client's pawn works as expected. After connecting, the c ...

World Partition grid priority setting taken into account last

UE - World Creation - Worldbuilding Tools - World Partition - Feb 11, 2025

From licensee:Editor Grid priorities setting will get overruled in code giving the user false feeling of control – smaller grid cells can load before larger grid cells on the same layer even if the ...

Mover ensure triggered when engine is running in the background

UE - Gameplay - Player Movement - Mover - Feb 11, 2025

When the engine is running in the background, the following ensure may be hit in NetworkPredictionService_Interpolate.inl: npEnsure(ToFrame == INDEX_NONE || LocalFrame - ToFrame < Frames.Buffer.Cap ...

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 ...

DMX component in world partitioned level fails cook

UE - Virtual Production - IO - DMX - Feb 10, 2025

Since UE5.5, RegisterComponent has been called during cook process, So unnecessarily references from DMXLibrary to DMXComponent has been added.  There is a workaround to avoid adding references : ...

[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.  ...