Unreal Engine Issues
Unreal Engine Issues
UE5.6+ - Mutable - IDPrefix crash when combining Child Objects, Add to Mesh Component and Extend Mesh Section.
UE - Anim - Mutable - Jul 21, 2025So the issue seems to be a combination of Add To Mesh Component and Extend Mesh Section. I've tried this in Epic Launcher 5.6, 5.6 in-house modified engine as well as ue5-main 5.7 from git (editor ...
Regression with RecomputeTangents on SkeletalMeshes in 5.6
UE - Graphics Features - Jul 21, 2025Licensee noticed a regression in 5.6 where the non-masked recompute tangents option doesn't work anymore. The option is called "Enabled with no mask" in 5.6 but "All" in 5.5. Under the hood, this se ...
UMaterialFunctionInterface not being tagged as BlueprintType makes some editor scripting scenarios difficult
UE - Rendering Architecture - Materials - Jul 21, 2025UMaterialInterface 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, 2025Enabling 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, 2025On 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, 2025This 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, 2025Reported 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, 2025Node 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, 2025Only 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, 2025Automatically generated navlinks are failing to be detected by FNavMeshNodeFlags::IsNavLink. The area flag assigned to the navlink end points is not including the NavLinkFlag. ...