Smart Link inactive by default when NavLink is a ChildActor

UE - AI - Navigation - Oct 14, 2025

When placing a NavLinkProxy in ChildActor, the link is not enabled by default. In this situation, setting SetSmartLinkEnabled to true does not establish the connection. You must first set it to fal ...

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 ...

User-defined InstancedStaticMeshComponent subclass misbehave in SCS Editor

UE - Framework - Blueprint Editor - Oct 13, 2025

Context Users can create InstancedStaticMeshComponent (ISMC) (blueprint) subclasses. Any ISMC class can be added to an actor blueprint. When a mesh is selected and transforms are added to the Insta ...

[AI] StateTree Category = Input validation doesn't validate child properties

UE - AI - StateTree - Oct 10, 2025

Normally if you have a property in your state tree instance data of the input property(Category = Input), when you compile the state tree, you will get errors if the property does not have a binding ...

When exporting from a level sequence, the LOD for the bones is based on the camera distance, instead of using LOD0

UE - Anim - Sequencer - Oct 9, 2025

When exporting a level sequence to an animation sequence, the bones used will be based on the LOD for the current camera location, instead of exporting LOD0. This is very noticable if you pull the ...

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 ...

Crash at compile time when using a VariableSet node with a local variable created by pasting a private property

UE - Framework - Blueprint - Oct 7, 2025

When a property is created in this way, a local variable with a Private flag is generated. Since such a variable is generally not desirable, it would be better to remove the Private flag upon pastin ...

HZB Occlusion causes large stalls on the render thread

UE - Rendering Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...