I just started experiencing this problem. I go to Microsoft Word -> Open Recent and I get the spinny beach ball. After a long wait, a Mac OS dialog pops up saying "There was a problem connecting to the volume 192.xxx.xxx.xxx". I click "OK", the dialog goes away, but Word is still unresponsive, the beach ball still spins and the message eventually pops up again. And so on. The only way out is to force-quit Word.
I'm having the same problem with Excel.
I'm running High Sierra on a MBP, and the latest MS Office (all up to date).
If I directly open a file it seems to work (mostly, though Word was having a problem with it today).
The only fix seems to be to actually connect to that server.
Seems like something somewhere is "stuck" looking for that server. How can I find/unstick it?