I have been importing XML files recently and there is a catch 22 that happens a lot.
After you select Import-XML the finder window opens so that you can select the file you want to open.
But once you select the file, Dorico brings up another dialog box which is BEHIND the finder one, so you can’t actually read or respond to the options, and you can’t close (or move) the finder window because the system is waiting for a response to the Dorico dialog first.
The workaround (when I remember) is to move the finder window to the side of the screen before selecting a file to open, but sometimes I forget and then have to do a Force Quit to get out of the stuck loop.
MACOS high Sierra