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

UE - Runtime - Simulation - 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 ...

Division by zero in FAnimNode_StrideWarping::EvaluateSkeletalControl_AnyThread

UE - Anim - Gameplay - Sep 29, 2025

When an Actor's CustomTimeDilation is 0.0, functions FActorTickFunction::ExecuteTick() and FActorComponentTickFunction::ExecuteTickHelper() will call AActor::TickActor() and UActorComponent::TickCom ...

Custom Depth range is different than Pixel Depth range

UE - Rendering - Graphics Features - Sep 25, 2025

Shaders that compare custom depth and pixel depth get wrong output values because the ranges are different. This error is most noticeable over large distances. The difference in ranges is due to t ...

NaN Present on IOS after UE5.6 Because of Removal of MobileSpecularGGX

UE - Platform - Mobile - Sep 24, 2025

In UE5.6 MobileSpecularGGX was removed and now mobile devices also run D_GGX. The problem is that there are still cases where very bright values are produced (image 1) and thus NaNs appear in the Bl ...

FKeyHandle internal static atomic counter can overflow on long running games depending on usage pattern

UE - Anim - Sep 24, 2025

Structure FKeyHandle stores an internal index, which is initialized from a static atomic counter in the default constructor: +----- FKeyHandle::FKeyHandle() { | static std::atomic<uint32> LastKey ...

Xcode 26/16.4 Metal Toolchain generates metallib's that are not compatible with iOS 16

UE - Platform - Apple - Sep 23, 2025

Below is the error output from FirstPerson template as a C++ project: {+}../../../FirstPerson58CPP/Content/firstperson58cpp_sf_metal_es3_1_ios-metal_es3_1_ios.0.metallib, 5881486 bytes!2025-09-23 1 ...

Mutable constant texture variable with ClipUV mask only works with new experimental dynamic variable is connected as well

UE - Anim - Mutable - Sep 22, 2025

We are attempting to use Mutable in 5.6.1 and have encountered an issue which we are not sure how to resolve. The issue occurs when using the ClipWithUVMask node. In short we have a customizable o ...

Calling FOnlineIdentitySteam::GetLinkedAccountAuthToken without an internet connection won't execute callback delegate for WebAPI token type

UE - Online - Sep 22, 2025

For the "WebAPI" TokenType, the call to execute the delegate is missing in the case where the SteamUserPtr is null or if BLoggedOn is false for the SteamUserPtr, so GetLinkedAccountAuthToken will ju ...

Seam visible when using a material with BumpOffset on a Nanite mesh

UE - Graphics Features - Nanite - Sep 18, 2025

When a material that uses BumpOffset is fed into the Emissive Color of Surface Opaque Default Lit material and then applied to a nanite mesh, a visible seam can be seen along edges and the intersect ...

Changing per layer parameters in a layered material that writes to RVT can cause temporary visual corruption

UE - Rendering - Architecture - Sep 12, 2025

When using a layered material that writes to a runtime virtual texture. Sometimes when modifying a layer parameter in the material instance editor. The cached material data in the runtime virtual ...