Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello,
The quickest fix right now is to run an Online Repair of Office 2013.
Open Settings > Apps > Installed apps, find Microsoft Office 2013, select the three dots, choose Modify, approve Yes, pick Online Repair, then Repair. Stay connected to the internet, let it finish, restart Windows, then open Word or Excel and let Office do the first run setup.
If you do not see Modify in Settings, open old Control Panel > Programs and Features > Microsoft Office 2013 > Change > Online Repair, then complete the same steps.
Tell me how that goes and I will suggest the next step if needed.