UMaterialFunctionInterface not being tagged as BlueprintType makes some editor scripting scenarios difficult

UE - Rendering Architecture - Materials - Jul 21, 2025

UMaterialInterface is BlueprintType, but UMaterialFunctionInterface is not. This makes it difficult to port some BP logic that works with materials to the material layer system. Crystal Dynamics wou ...

Enabling Strip Source Data On Cook on Geometry Collection is also stripping the Anchor flag of cooked assets

UE - Simulation - Physics - Jul 20, 2025

Enabling Strip Source Data On Cook on Geometry Collection (GC) is also stripping the Anchor flag of cooked assets. The licensee has reported that once they do a build the Anchors disappear and GCs t ...

Crashes after destroying a skeletal mesh attached via socket name (not bone name), the destroyed mesh remains welded.

UE - Simulation - Physics - Jul 18, 2025

On welding physics bodies during primitive component attachment, UPrimitiveComponent::WeldToImplementation() calls GetRootWelded() and then GetBodyInstance() on the returned root. This searches by b ...

Crash when travelling during ability activation when URL contains "#"

UE - Framework - Jul 18, 2025

This issue is related to [Link Removed], where the "?listen" option sent on the URL to clients could cause issues with RPCs being called locally during travel. The fix to remove the "?listen" option ...

Assets on paths with speed parameters are sped up in Path Tracer exports

TM - Rendering - Jul 18, 2025

Reported in SF [Link Removed] In Path Tracer renders, all paths with a speed component (vehicles, bicycles, custom) will render at an increased speed than specified in the exported render. This is ...

Enabling Substrate causes MaterialGraph node previews to render black

UE - Graphics Features - Substrate - Jul 16, 2025

Node previews in MaterialGraph with Substrate enabled render solid black in 5.6. The latest 5.5 engine does render previews correct with substrate enabled. ...

Mover standalone backend allows non-persistent sync structs to carry over between frames

UE - Gameplay - Player Movement - Mover - Jul 16, 2025

Only certain sync state structs are intended to persist between frames. These are configured via MoverComponent's PersistentSyncStateDataTypes array. There appears to be a bug in the way the standa ...

[AI] Automatically generated navlinks do not contain the poly flag for being a navlink.

UE - AI - Navigation - Jul 16, 2025

Automatically generated navlinks are failing to be detected by FNavMeshNodeFlags::IsNavLink. The area flag assigned to the navlink end points is not including the NavLinkFlag. ...

AddOrUpdateWarpTargetFromComponent behaving incorrectly when using a SceneComponent with non-identity scale

UE - Anim - Gameplay - Jul 15, 2025

When using AddOrUpdateWarpTargetFromComponent you can pass in a SceneComponent, Relative Location and Rotation as well as optionally choosing to have the warp target follow the object if it moves.If ...

URuntimeVirtualTextureComponent::RequestPreload not working for some edge cases

UE - Rendering Architecture - Jul 15, 2025

A licensee has reached out to us to inform us that the logic for preloading at times fails to account for adaptive virtual textures when the requested mip level is not in the shared AllocatedVirtual ...