When I open an office document, I am getting an error message, I do select repair now and the document will open. But then closes on its own within 5 minutes. Document will save when it is open but it does not seem to be repairing as this is recurring

Run a full Online Repair of Microsoft 365 from Windows Settings; the Repair Now button in the error dialog has not completed the broader installation repair needed when both Word and Excel are affected.

Run Online Repair

1. Save your work and close all Office applications, including Word, Excel, Outlook, and OneNote.
2. Open the appropriate Windows page:
   • Windows 11: Right-click Start → Installed apps.
   • Windows 10: Right-click Start → Apps and Features.
3. Find Microsoft 365 or Microsoft Office.
4. Select the three dots beside it, if shown, and choose Modify.
5. For the common Click-to-Run installation, select Online Repair → Repair. Do not select Quick Repair.
   • If an MSI repair screen appears instead, select Repair → Continue.
6. Allow the process to finish without opening an Office application.
7. Restart Windows, then open Word and Excel normally and leave them running long enough to verify that they no longer close.

Online Repair repairs the entire Office suite, even if initiated for a problem seen in Word or Excel. Microsoft distinguishes it from Quick Repair, which only detects and replaces corrupted files.^1^ A closely matching case affecting multiple Office applications also identifies Online Repair as the next step when the error dialog’s Repair Now action does not resolve the problem.^2^

If Online Repair does not resolve it

Test each application in Office Safe Mode, which starts it without automatically loading add-ins and certain customizations:

1. Press Windows key + R.
2. Run one command at a time:
   • Word: winword /safe
   • Excel: excel /safe
3. Keep each application open for longer than the usual five-minute failure period.

Microsoft documents these commands and Safe Mode’s use for identifying an add-in or extension that interferes with startup.^3^

If an application remains stable in Safe Mode:

1. Go to File → Options → Add-ins.
2. At the bottom, select COM Add-ins from Manage, then select Go.
3. Clear one add-in, select OK, and restart the application normally.
4. Repeat until the application remains stable.
5. Leave the faulty add-in disabled, or obtain an updated version from its publisher.

Testing add-ins individually identifies which one causes the failure.^4^

Final fallback: clean reinstall

If Word and Excel still fail after Online Repair and also fail in Safe Mode, uninstall and reinstall Microsoft 365:

1. Use Microsoft’s uninstall troubleshooter on the affected PC.
2. Follow its prompts and restart Windows when requested.
3. Reinstall Microsoft 365 using the Microsoft account associated with the subscription.

The troubleshooter supports Microsoft 365 and Office 2021/2019/2016 on Windows 10 or later, but it currently cannot uninstall Office 2024.^5^

Avoid manual registry deletion unless Microsoft Support specifically directs it; the supported Online Repair and uninstall troubleshooter are safer first.

References

1. Repair an Office application | Microsoft Support
2. All microsoft office applications Excel, Word, Outlook, Etc. open with error and cannot be used - Microsoft Q&A
3. Open Office apps in safe mode on a Windows PC | Microsoft Support
4. I get a "stopped working" error when I start Office applications on my PC | Microsoft Support
5. Microsoft 365 subscription features aren't available in Office apps | Microsoft Support