I never observed this problem until now. Apple recently replaced my MacBook Pro with a new equivalent unit, and I set it up from scratch by copying files from a backup, reinstalling software, etc. Right now,
whenever I try to open a Word file from within a Word open/save dialog, I see the "Grant File Access" dialog if I haven’t previously used Word to open the file on the new computer. If I double-click a file
from the Finder, I don’t see this error message.
I’ve checked permissions, and they seem to be fine. On what basis does Word need “additional permissions,” and what are they? I’m running OS X 10.11.3 without any font management utilities.