In the mean time, if you have a window that has disappeared with changes to the file, and you need to recover it, select "Quit" from the menu, then "Cancel" when asked if you want to save changes - this will restore the window.
In the mean time, if you have a window that has disappeared with changes to the file, and you need to recover it, select "Quit" from the menu, then "Cancel" when asked if you want to save changes - this will restore the window.