Variant Manager: LevelVariantSets asset corruption after rename or duplicate

UE - Editor - Open File Formats - Variants - Oct 24, 2025

When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...

Missing materials on the rear lights and windows of library vehicles

TM - Content - Oct 24, 2025

Reported in SF [Link Removed] The rear light material and window materials on Twinmotion library vehicles are not present on many vehicles in TM 2025.2. Confirmed affected vehicles are in the foll ...

VulkanStagingBuffers stat continually to grows.

UE - Platform - Mobile - Systems - Oct 24, 2025

On Android phones, VulkanStagingBuffers continually grows when the scene is static. From looking at FStagingManager, it appears the VulkanStagingBuffers atat is only updated on buffer acquisition, ...

[5.6 bug] FbxImportUI settings physics_asset configuration appears to have no effect

UE - Editor - Open File Formats - FBX - Oct 24, 2025

My fbx import script that used to work in 5.4 stopped creating physics asset when ran in 5.6 i checked the api and doesnt seem like it has changed between the two versions. below is the fbx import s ...

“None” option removed from “Preview Game Language” in Editor Preferences since UE 5.6

UE - AI Workflows - UI Systems - Oct 24, 2025

In Unreal Engine 5.5 and earlier, users could select “None” as the Preview Game Language in the Editor Preferences. Starting from UE 5.6, this “None” option is no longer available. Based on source ...

Lumen reflections break when the normals don't match the pixel depth information.

UE - Rendering - Features - Lumen - Oct 23, 2025

Lumen Reflections can leave black spots in chrome materials with strong normals. Also tested on UE 5.5, CL: 41545209 and UE 5.6, CL: 45232827 ...

CLI: Exporting COLMAP with selected mask layer doesn't export the masks.

RS - Alignment - Oct 23, 2025

When using the -exportRegistration command with an XMP parameters file, where the mask layer is selected for export, geometry images are exported instead. The mask export is successful from the use ...

Swarm Agent Binaries Missing in Launcher 5.7 Preview

zComponent - Archive - Oct 23, 2025

The Swarm binaries are missing from Engine\Binaries\DotNET in the 5.7 Preview launcher version of the engine. This causes any lighting build or precomputed static visibility builds to fails due to t ...

Snap to nearest spline point no longer working in 5.6. Right clicking on a spline point and using the option “Snap to nearest spline point" will no longer snap that point to any nearby spline and will sometimes cause the spline to snap to itself.

UE - Gameplay - Oct 22, 2025

Context: When editing SplineComponents in the level viewport, right clicking a spline point has a context menu action "Snap to nearest spline point". Problem: The problem is, Snap to nearest spline ...

RuntimeCellTransformers can result in increasing the instance count when a BP instance is not destroyed.

UE - Engine Scaling - Streaming - Oct 22, 2025

The problem is related to the SimpleConstructionScript that executes on the BP instances after the transformer.  The problem also happens at cook time as the SCS is executed when the package is sav ...