Failed to generate Nanite data for mesh with bDoFastBuild enabled

UE - Graphics Features - Nanite - Oct 1, 2025

If "bDoFastBuild" is enabled on a Static Mesh asset, in-editor it will never be able to have Nanite data built for it, preventing the Static Mesh from using Nanite. There is no way to fix this issu ...

Update LookupProxy chooser evaluation to work with soft object references.

UE - Anim - Gameplay - Oct 1, 2025

Soft object references in proxy tables, when evaluated return a nullptr, instead of the soft object reference to load. ...

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 ...

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 ...

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 ...

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 ...

Wrong density calculation in UBodySetup::CalculateMass

UE - Simulation - Core - Sep 29, 2025

Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...

nDisplay Regression: Public header DisplayClusterViewport_OverscanSettings.h now includes internal header Math/MarginSet.h, breaking clients' code

UE - Virtual Production - nDisplay - Sep 29, 2025

On the nDisplay plugin code, CL 44773085 from August 12 introduced a new struct template TMarginSet and changed struct FDisplayClusterViewport_OverscanSettings to use it. However, the latter is defi ...