FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code

UE - Niagara - Scalability - Oct 1, 2025

Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...

Performance issue with the material dock

TM - Tools - Oct 1, 2025

See video. Tested on 2025.2  In a project where you have a lot of materials, it take a long time to open the material dock. Here around 20 seconds. And that's at each time you want to enter it. Y ...

Shader Complexity View not working in Deferred Mobile Preview

UE - Platform - Mobile - Sep 30, 2025

Proposed workaround:add in FMobileSceneRenderer::RenderDeferredMultiPass (MobileShadingRenderer.cpp): #if WITH_DEBUG_VIEW_MODES if (ViewFamily.UseDebugViewPS()) { return; } #endif // WITH_DEBU ...

Pathtracer - Odd results from any material adjusting normals to complement world position changes

UE - Graphics Features - Path Tracer - Sep 30, 2025

Someone on the forums is reporting a possible bug with Pathtracer and any material that adjusts normals to complement world position changes. See pic attached. Reporting forum thread:https://foru ...

BoxOverlapActors fails to catch an Overlaped actor with a particular scale, from a particular position

UE - Simulation - Core - Sep 30, 2025

BoxOverlapActors fails to overlap a scaled Floor actor with a particular scale, from a particular position and extent. The setup is really specific and described in Steps to Reproduce. The required ...

Some .tmi files from previous versions cannot be used in TM2025.2

TM - Core - Sep 30, 2025

Some .tmi files appear, while others don’t.The customer mainly uses Blender and SketchUp.On the customer side, even the TM asset “Metal workout desk DCL” has the same issue.On my (Syuya Mukai) side, I ...

Skeleton retarget settings are lost when importing/reimporting a mesh with bone hierarchy changes

UE - Editor - Content Pipeline - Import and Export - Sep 30, 2025

Importing a mesh that changes the hierarchy of a related skeleton causes the animation retarget settings on the skeleton to be lost. This is because in UInterchangeSkeletalMeshFactory::EndImportAss ...

Rendered panoramas using Lumen may be overexposed

TM - Rendering - Sep 30, 2025

Reported in SF [Link Removed] Lumen Panorama renders in 2025.2 may appear overexposed compared to the viewport, or when comparing the same render produced in 2025.1.1 This only appears to occur wi ...

Merge Actors (Simplify) is broken with Substrate Shader Models Node

UE - Graphics Features - Substrate - Sep 29, 2025

Substrate Materials cannot be baked when Meshes are merged using the "Simplify" method. All textures except for the normal are reduced to a single black parameter. The normal texture produced does n ...

Many downloaded cloud items cause a performance issue when booting Twinmotion

TM - Interoperability - Sep 29, 2025

See slack thread: [Link Removed] Resume : In the context of the object substitution for Revit, when TM starts, it exports a csv listing the available objects and their corresponding thumbnail. This ...