User-defined InstancedStaticMeshComponent subclass misbehave in SCS Editor

UE - Framework - Blueprint Editor - Oct 13, 2025

Context Users can create InstancedStaticMeshComponent (ISMC) (blueprint) subclasses. Any ISMC class can be added to an actor blueprint. When a mesh is selected and transforms are added to the Insta ...

Skylight Leaking Tint in Reflection

UE - Graphics Features - Oct 10, 2025

From 5.6 onwards, Skylight Leaking is much stronger in reflections than in the world. Also tested on //UE5/Release-5.6, CL 45232827 ...

When exporting from a level sequence, the LOD for the bones is based on the camera distance, instead of using LOD0

UE - Anim - Sequencer - Oct 9, 2025

When exporting a level sequence to an animation sequence, the bones used will be based on the LOD for the current camera location, instead of exporting LOD0. This is very noticable if you pull the ...

Actors transforms broken in cooked builds when their parent is an IsEditorOnlyActor

UE - Foundation - Data Pipeline - Cooker - Oct 7, 2025

When creating a hierarchy of Actors in the Outliner, the transform of the "child" actors will be reset if their Parent's IsEditorOnlyActor property is true.  The project in the EPS case is using ...

[Material Substitution] Missing Material IDs in exported CSV in 2025.2

TM - Interoperability - Oct 7, 2025

Reported in SF [Link Removed] When exporting material IDs in 2025.2, downloaded materials appear to be missing from the exported CSV. In 2025.2, it appears that only local materials are included i ...

HZB Occlusion causes large stalls on the render thread

UE - Rendering Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...

Vertex color does not work on Skeletal Mesh with Nanite enabled

UE - Graphics Features - Nanite - Oct 7, 2025

Nanite enabled skeletal meshes don't work with materials containing a vertex color node. The vertex color material does work for non-Nanite skeletal meshes and Nanite-enabled static meshes. ...

Converting a mesh to Nanite merges mesh sections with the same material index, but with different material overrides

UE - Anim - Mutable - Oct 6, 2025

When a mesh with multiple sections which point to the same MaterialIndex but have different settings enabled (e.g. bCastShadow is enabled on only one section) is converted to Nanite, the material sl ...

Long load time for files with large numbers of trees in 2025.2

TM - Core - Oct 6, 2025

Reported in SF [Link Removed] User reports that multiple files with large amounts of trees take substantially longer to load in TM 2025.2 compared to 2025.1.1. Confirmed with one of the user's fil ...

Import then cancel while file is read leads to potential crash

TM - Interoperability - Oct 6, 2025

1/ Import a file with mootools such as an fbx 2/ while the file is still read, cancel the import Result : may crash few times after (when theoretically the file has finished being read) - not repr ...