Steps to reproduce:
1. Create new Unity project
2. Press on “Unity Version Control” button (next to the Asset Store button)
3. “Unity Version Control” should open a new tab next to Console tab
4. Go to Settings > General
5. Switch Editor Theme from Dark to Light or vice versa
6. Observe the Console window

Actual results: No errors are thrown in the Console window when switching Editor Theme
Expected results: Error is thrown when switching Editor Theme:
{code:java}
NullReferenceException: Object reference not set to an instance of an object
Unity.PlasticSCM.Editor.ViewSwitcher.OnDisable () (at ./Library/PackageCache/com.unity.collab-proxy/Editor/ViewSwitcher.cs:205)
Unity.PlasticSCM.Editor.PlasticWindow.ClosePlastic (Unity.PlasticSCM.Editor.PlasticWindow window) (at ./Library/PackageCache/com.unity.collab-proxy/Editor/PlasticWindow.cs:1096)
Unity.PlasticSCM.Editor.PlasticWindow.OnDisable () (at ./Library/PackageCache/com.unity.collab-proxy/Editor/PlasticWindow.cs:283) {code}

Reproducible with versions: 2021.3.47f1 2022.3.55f1, 6000.1.0a9

Tested on (OS): macOS Sequoia 15.1.1 (Intel) and (M1)

Notes:

•  Might need to switch themes multiple times from dark to light or vice versa for error to appear