Steps to reproduce:

1. Open the attached project
2. Open the TestScene
3. In the Multiplayer Play Mode window, start a Virtual Player
4. Enter Play Mode
5. In the Virtual Player window, press the Layout button
6. Enable Hierarchy 
7. Disable Hierarchy
8. Re-enable Hierarchy (Hierarchy window does not open and throws warnings related to another case)
9. Try disabling Game and Console panels

Actual results: The Virtual Player window is duplicated. One copy displays the Hierarchy panel, and the other displays the Game and Console panels. "An editor should only have 0 or 1 TopView." Warnings and Errors are also thrown

Expected results: Re-enabling the Hierarchy panel does not cause any warnings or errors

Reproducible with versions: 2.0.0-pre.1 (6000.3.0b4, 6000.4.0a1)

Not reproducible with versions:  1.6.1 (6000.0.59f1, 6000.2.5f1)

Tested on (OS): macOS 26.0

Notes:

• Only reproducible with Hierarchy V2. It can be enabled via Preferences -> General -> Use new Hierarchy Window

Full Error message:

• An editor should only have 0 or 1 TopView. [2]

UnityEngine.Debug:Assert (bool,string)
Unity.Multiplayer.PlayMode.Editor.TopView/<>c__DisplayClass3_0:<CreateGUI>b__5 () (at /Users/bokken/build/output/unity/unity/Modules/MultiplayerEditor/Managed/MultiplayerPlayMode/Workflow/UI/TopView.cs:121)
UnityEditor.EditorApplication:Internal_CallUpdateFunctions () (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorApplication.cs:392)