I can confirm that the fix in branch lp:~larsu/notify-osd/fix-1189281 fixes the crash, but it still doesn't display the notification bubble (probably still remains the wrong behaviour with in dnd_has_one_fullscreen_window function for don't disturbe mode)
I can confirm that the fix in branch lp:~larsu/notify-osd/fix-1189281 fixes the crash, but it still doesn't display the notification bubble (probably still remains the wrong behaviour with in dnd_has_ one_fullscreen_ window function for don't disturbe mode)