Symptom:
Opening Word or Excel documents on a network share opens a New Document window and not the selected file.
Cause:
Corrupt Office profile folder.
Resolution:
Log in as Administrator, rename (or delete) the profile folder.
C:\Users\%username%\AppData\Local\Microsoft\Office
I renamed mine to OLD-Office so I could rename it back if I caused serious issues.
Reboot, log in as your regular user and open the document from the network location.
You might get a notification that the profile is corrupt (I didn’t), which is merely a notification. It will rebuild it and open the document.