Hi, I am an Independent Advisor, and welcome to Microsoft Q&A.
I understand you are having an error with Microsoft Word when opening it up.
Have you tried repairing Microsoft Office?
Please follow the steps below.
Press Windows + I to open Settings.
Go to Apps > Installed apps (or Apps & features in some versions).
Scroll and find Microsoft Office (or Microsoft 365).
Click the three dots (…) > Modify.
Choose Quick Repair first > Repair.
If the problem persists, choose Online Repair (requires internet).
Online Repair will uninstall and reinstall your Microsoft Office Suite, this process may take a while to finish.