Hey again!
So to confirm, it’s EVERY Word document not just this one that won’t open?
Also, you ARE able to open other documents on the Desktop, etc., just not Word documents?
Can you also go to Apple > About This Mac > System Report,
Under Software, click on Applications, can you scroll down until you find Word, and click on it to show the info below, and especially if you see two of them?
Tough to say if permissions just need to be applied to a certain location, or app, or if Word just needs to be uninstalled/reinstalled.
I think a good test maybe to move one or some of the documents to the Shared folder:
Finder > Go > Computer > Macintosh > Users > Shared.
Create a new administrator account in System Preferences > Users and Groups, log out, and log into the new user.
Navigate to the same Shared folder, are you able to open the documents there? That will tell us a lot,
Likewise, a good test would be safe mode, some third party apps may not work right, but all we need to do is see if one of the documents opens in Word while in safe boot:
https://support.apple.com/guide/mac-help/start-up-your-mac-in-safe-mode-mh21245/mac
Also, are the documents Syncing to a cloud service? iCloud/One Drive/Dropbox etc?
Thanks! Let me know how it goes!