Specular Scale 0 on Light still affects Groom asset

UE - Rendering Architecture - Jul 30, 2025

When a light's Specular Scale is set to 0, the specular still affects hair / groom assets. The specular of other assets (like a shiny static mesh in the scene) is properly affected by the change.  ...

Unloading a World Partition region during nested Level Instance inline editing prevents exiting editing mode

UE - World Creation - Worldbuilding Tools - Level Instances - Jul 28, 2025

In the case of a single-layer Level Instance, actors are still referenced even when the region is unloaded. However, in the case of nested Level Instances, the level being edited is discarded when t ...

Mutable RemoveMesh node with data from DataTable

UE - Anim - Mutable - Jul 28, 2025

Hi, We are trying to use Mutable plugin to avoid clipping using the RemoveMeshNode with data from DataTables. However we are having trouble with the most basic example of our idea. We have a Data ...

ULevelSequence trying to duplicate a REINST_ class when creating new custom binding in ConvertOldSpawnables()

UE - Framework - Blueprint Compiler - Jul 23, 2025

The assert that we're hitting is:Cannot replace existing object of a different class.  New Object: /Engine/Transient.REINST_BPC_NPC_VFX_C_230 /Game/Maps/[REDACTED]/Levels/[REDACTED]/LevelSequence/ ...

Farfield shadow in lumen scene

UE - Graphics Features - Jul 21, 2025

Shadows in the Lumen Scene from Lumen's Direct Lighting do not match the world when in the Lumen Far Field. This leads to shadows where there should not be any, and missing shadows where there shou ...

Montage Editor: Mouse Wheel Cannot Scroll to the Bottom of notify section when there are many track.

UE - Anim - Runtime - Jul 21, 2025

When a large number of notify tracks are added in the Montage Editor, the mouse wheel scroll does not allow the user to reach the bottom-most tracks. Only by manually dragging the scrollbar can the ...

Performance slowdown when ray tracing is disabled due to SetResidencyPriority

UE - Rendering Architecture - RHI - Jul 17, 2025

When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...

Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops

UE - Niagara - Jul 16, 2025

Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...

Bake Pose is not applied correctly when using LODSettings asset

UE - Anim - Rigging - Jul 16, 2025

The Bake Pose setting does not work when using a SkeletalMesh LODSettings asset. After the change in CL22878911, the BasePose in the LODSettings asset is no longer copied to the BakePose in the skel ...

When moving actors to the current level, their label is reset and displayed incorrectly on the Scene Outliner until the next time it is refreshed

UE - Editor - Workflow Systems - Jul 14, 2025

This is a regression, it worked correctly up to UE 5.4, but repros on UE 5.5 and 5.6. Also, this seems related to [Link Removed], which was fixed by CL 40649716/40649749 and integrated into UE 5.6, ...