Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Highly likely the installation of m365 is corrupted or didn't complete properly. There are a few options to fix this but let's try the simplest path
Update Office first
- Open Word and create a blank document if it opens without error.
- Go to File > Account > Update Options > Update Now.
- If Update Now is not shown, select Enable Updates first.
- Restart the PC after updates finish.
If that doesn't work, or if Word crashes before it will run the update, you'll need to dig into system settings.
Run an Office repair
- Go to Start > Settings.
- On Windows 11: Apps > Installed apps.
- On Windows 10: Apps and Features.
- Select Microsoft 365 or Office > Modify.
- For Click-to-Run, choose Online Repair > Repair.
- For MSI-based installs, choose Repair > Continue.
- Restart the PC when the repair finishes.