If an updated window is trying to be closed by the user, then the system asks whether the user wants to save the contents?
Choosing yes will save and close the window, choosing no will not save and close the window, choosing cancel will not save but not close the window.
When we choose save from the context menu (or press Ctrl+S) :
Choosing yes will save, no will abort the save operation. If everything goes smoothly and the content is saved, this window is displayed:
If not, then this window with the extra error information will be displayed:
Of course the extra error information can vary according to the context.