GeneSplicerModule has linking errors in a Development target

MetaHuman - Oct 16, 2025

The FArchiveMemoryStream class is defined in GeneSplicerModule and RigLogicModule. This generate linker error as this doesn't respect the "One Definition Rule"  1>Module.GeneSplicerModule.cpp.ob ...

Mutable - morph does not work for a skinned mesh with more than one uv channel

UE - Anim - Mutable - Oct 16, 2025

The morph functionality fails to change when the skinned mesh contains more than one UV channel in a Customizable Object. ...

Curve Debugger window is broken when viewing curves in the Anim Sequence editor

UE - Anim - Runtime - Oct 15, 2025

The curve debugger is currently broken when viewing curves on anim sequences. It seems that only metadata/skeleton curves are displayed, and those aren't updating correctly or showing their type (m ...

All Megascan asset libraries are missing

TM - Core - Oct 15, 2025

All Megascans assets no longer appear in Twinmotion 2025.2 hotfix (46767548). Other libraries do not appear to be affected. ...

Light Leak Issue in Modular Buildings (Lumen HZBTraversal)

UE - Graphics Features - Lumen - Oct 14, 2025

Starting in Unreal Engine 5.6, disabling "r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal" can lead to light leaking between adjacent or overlapping meshes. Also tested on Release-5.6, CL: 4523 ...

Ensure in FOnlineSubsystemSteam::Shutdown when using OSS Adapter

UE - Online - Oct 13, 2025

This looks to occur because of the order in which the OSS Adapter module and Steam OSS module are shut down. The OSS Adapter holds onto references to the OSS's interfaces, so when the Steam OSS modu ...

Ensure triggered in FBoundsCacheElement::GetValue when adding ISM instances in Construction Script

UE - AI - Oct 8, 2025

An ensure is triggered in FBoundsCacheElement::GetValue when adding instances to an InstancedStaticMeshComponent inside a Blueprint’s Construction Script. This occurs when the ISM component is navig ...

CppCompileWarningSettings.NonInlinedGenCppWarningLevel messages should contain Warning\Error

UE - Foundation - Cpp Tools - UnrealBuildTool - Oct 8, 2025

The messages emitted when CppCompileWarningSettings.NonInlinedGenCppWarningLevel is set to Warning\Error should contain the literal so the tools pick them up and react accordingly. From the EPS c ...