*Steps to reproduce:*
# Open a Unity project
# Open UI Builder via Window > UI Toolkit > UI Builder
# Undock the window so that it is floating
# Make a change so that there are unsaved changes (e.g. drag a VisualElement into the Hierarchy from the Library)
# At the top right of the editor, press on the Layout drop-down then 'Reset All Layouts'
# In the 'Revert All Window Layouts' pop-up window, press Continue
# In the 'Unsaved Changes Detected' popup, press Cancel

*Actual results:* A 'Missing Default Layout' pop-up appears, prompting the user to either Quit or Revert Factory Settings.

*Expected results:* The Reset Layouts process is cancelled and the windows remain as they were.

*Reproducible with versions:* 
* 6000.0.13f1
* 2022.3.40f1
* 2021.3.40f1 (see notes)
* 2021.3.32f1 (see notes)

*Not reproducible with versions:* 
* 2021.3.31f1

*Can’t test with versions:* - 

*Tested on (OS):* Windows 10, Windows 11

*Notes:*
* On 2021.3, the Unsaved Changes Detected popup may display twice, so press cancel both times