Viewport stuttering during orbit/zoom navigation

UE - Rendering - Graphics Features - Dec 17, 2025

Received a report of persistent stutters in the editor when trying to navigate in the viewport, including asset editor viewports like the Skeletal mesh editor and control rig editor. Hardware used ...

A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction

UE - Runtime - Character - Dec 16, 2025

Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...

[WorldPartition][CellTransformer] ISM Cell Transformer breaks component hierarchy when child component are transformed

UE - World Creation - Worldbuilding Tools - World Partition - Dec 15, 2025

This case is related to [Link Removed] Closed but is not a duplicate.  Please make sure to download the attached project a ...

OcclusionFeedback may not be performant for primitives with large screensize

UE - Platform - Mobile - Dec 13, 2025

A licensee reported that the performance could be worse in some scenarios (probably a small scene with large objects) with OcclusionFeedback enabled ( 20fps up if disabled), tested on a Qualcomm 870 ...

Gameplay Tags sourced from a Composite Data Table do not reflect changes made to its parent tables

UE - Gameplay - Gameplay Tags - Dec 5, 2025

When a Composite Data Table is included in the "Gameplay Tag Table List" on the Project Settings, making and saving changes to one of its Parent Tables does not cause the Gameplay Tag Tree to refres ...

Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled

UE - Rendering - Architecture - RHI - Dec 3, 2025

When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...

PlayerCollision visualization incorrect on LandscapeSplineMesh when Nanite is enabled

UE - Rendering - Features - Nanite - Dec 3, 2025

From licensee: I’ve found an issue with the visualization of PlayerCollisions when using LandscapeSplineMesh with a mesh that has Nanite enabled. The Chaos collisions shown in the Chaos Visual Debu ...

Pass names appear as "RDGEvent" in Unreal Insights when r.rhisetgpucaptureoptions=1

UE - Rendering - Architecture - RHI - Dec 2, 2025

When capturing a trace in Unreal Insights, all r.rhisetgpucaptureoptions=1 (r.RDG.Events=3) all RDG pass events appear simply as RDGEvent, without the actual name due to the logic for RDG_EVENT_SCOP ...

Standalone Level Instance with WorldPartition world don't load in editor

UE - World Creation - Worldbuilding Tools - Level Instances - Dec 2, 2025

A WorldPartition map used as a level instance that's set to standalone mode doesn't load its actors in the editor. ...

Not all MidPhases are enumerated in TSimCallbackObject::OnMidPhaseModification

UE - Runtime - Simulation - Dec 2, 2025

Newly generated MidPhases are copied into the array accessible in the NarrowPhase after the OnPreSimulate callback is invoked. As a result, it is not possible to modify newly created MidPhases withi ...