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 ...

Soft angular constraints solve velocity like hard constraints

UE - Simulation - Core - Jul 17, 2025

Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...

Performance slowdown when ray tracing is disabled due to SetResidencyPriority

UE - Rendering Architecture - RHI - Jul 17, 2025

When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...

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. ...

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 ...

Drag-and-drop any cooked Blueprint class asset into the level viewport crashes the editor

UE - Framework - Blueprint - Jul 14, 2025

Dragging any cooked Actor-based Blueprint class asset into the level editor viewport will crash the editor when it has been configured to work with cooked assets. This is a regression that started ...