Project Auditor - 'Cannot save invalid window Failed to load' after closing editor with Project Auditor open

I open and close the editor (with no other windows present) I don't generate any items in the console after restarting the editor, but if I have the Project Auditor open when the Editor restarts it looks to log

Cannot save invalid window Failed to load  (UnityEditor.FallbackEditorWindow) to layout.
UnityEditor.WindowLayout:LoadDefaultWindowPreferences () (at /Users/richard.pickering/Documents/GitHub/unity2/Editor/Mono/GUI/WindowLayout.cs:107)

[Internal link]

Steps to reproduce:

1.  Open Editor
2.  Ensure you have no other Windows open
3.  Close the Editor and Reopen It
4. Notice no errors in the console
5. Now open the Project Auditor
6. Close down the Editor with this window open
7. Restart the editor
8. Notice the warnings in the console

Actual results: Warnings are shown after the editor restarts

Expected results: No errors are shown when the editor starts

Reproducible with versions: 

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): 

Notes: