How to fix this error?

Run an Online Repair of Microsoft Office from Windows 11 rather than relying only on the Repair Now button in the Excel dialog.

1. Run Online Repair

1. Close Excel, Word, Outlook, and all other Office applications.
2. Right-click Start and select Installed apps.
3. Find Microsoft 365 or Microsoft Office.
   • If Excel was installed separately, find Microsoft Excel instead.
4. Select the three dots (…) beside it, then select Modify.
5. For a Click-to-Run installation, select Online Repair → Repair.
   • If the installer instead displays an MSI-based Change your installation window, select Repair → Continue.
6. Complete the repair and restart Windows.
7. Open Excel and verify that it starts without the error.

Online Repair repairs the entire Office suite, even when only Excel is failing. It is more comprehensive than Quick Repair and may require an Internet connection.^1^

2. If Excel still fails, test Safe Mode

Safe Mode starts Excel without most add-ins and startup customizations:

1. Press Windows key + R.
2. Enter:

excel /safe

3. Select OK.
4. Check whether the title bar shows Microsoft Excel (Safe Mode).

If Excel opens successfully:

1. Go to File → Options → Add-ins.
2. At the bottom, select COM Add-ins under Manage, then select Go.
3. Clear all checkboxes and select OK.
4. Close Excel and start it normally.
5. If it now works, enable the add-ins individually, restarting Excel after each one, until the problematic add-in is identified.^2^

If Excel does not open in Safe Mode, the issue is not likely to be an add-in; continue with repair, updates, or reinstallation.^3^

3. If the problem remains

Try these in order:

1. Update Office, if another Office application opens:
   • Open Word or another Office app.
   • Go to File → Account → Update Options → Update Now.
2. Update Windows 11:
   • Open Start → Settings → Windows Update.
   • Select Check for updates, install available updates, and restart.
3. Reinstall Office if Online Repair and updates do not resolve it:
   • Before uninstalling, confirm that the Microsoft 365 subscription or Office license is associated with the Microsoft account used to install it.
   • Uninstall Office, restart Windows, and reinstall it from that account. Microsoft lists reinstallation after updates, add-in troubleshooting, and Office repair for persistent startup failures.^3^

References

1. Windows 11
2. Excel not responding, hangs, freezes or stops working
3. I get a "stopped working" error when I start Office applications on my PC | Microsoft Support