Unity Issue Tracker - “InvalidOperationException: HierarchyNode(8:1) not found“ error is thrown when creating a “Create Session” Multiplayer Widget for the first time with Hierarchy V2 enabled

Fixed

Fixed in 6000.3.1f1, 6000.4.0a6, 6000.5.0a3

Votes

Found in

Issue ID

Regression

“InvalidOperationException: HierarchyNode(8:1) not found“ error is thrown when creating a “Create Session” Multiplayer Widget for the first time with Hierarchy V2 enabled

-

Oct 30, 2025

Steps to reproduce:

Create a new Unity project using the Universal 3D template
Make sure Hierarchy V2 is enabled (Preferences > General > Use new Hierarchy window)
Install the Multiplayer Widgets package (com.unity.multiplayer.widgets)
Create a new Create Session GameObject (GameObject > Create > Multiplayer Widgets > Create > Create Session)
Observe the Console window

Actual results: “InvalidOperationException: HierarchyNode(8:1) not found“ error is thrown

Expected results: No errors are thrown

Reproducible with versions: 1.0.3 (6000.4.0a2, 6000.3.0b9, 6000.4.0a4)

Not reproducible with versions: 1.0.0, 1.0.3 (6000.4.0a1), 1.0.3 (6000.0.61f1, 6000.2.10f1)

Tested on (OS): MacOS Silicon Sequoia 15.6.1