Outlook has an error but it will not fix it

Follow these steps in order until Outlook opens normally.

1. Start Outlook in Safe Mode and disable add-ins
   1. Press Windows key + R.
   2. Type outlook.exe /safe and select OK.
   3. If Outlook opens, select File > Options > Add-ins.
   4. At the bottom, next to Manage, select COM Add-ins and then Go.
   5. Clear all check boxes to disable all add-ins, then select OK.
   6. Select File > Exit to close Outlook.
   7. Open Outlook normally (without /safe) and see if it works.
   8. To find the problematic add-in, re-enable add-ins one at a time:
      • Go to File > Options > Add-ins > COM Add-ins > Go.
      • Check one add-in, select OK, restart Outlook.
      • When Outlook fails again after enabling a specific add-in, disable that add-in and leave it off.
   Caution: Clear the check box to disable an add-in. Do not select an add-in and choose Remove, because that can delete it.
2. Run the Classic Outlook Advanced Diagnostics troubleshooter (for freezes / not responding) If Outlook still freezes or shows “not responding” when trying to fix the error, run the Classic Outlook Advanced Diagnostics tool on the same Windows device where Outlook is installed and make sure it is Windows 10 or later. Use the button in the article under “Many of these items can be automatically checked by the Classic Outlook Advanced Diagnostics troubleshooter” and follow the steps in the Get Help app. After it finishes, apply any fixes it suggests.
3. Check for known issues with data files If the error text mentions that something is wrong with a data file and asks to run the Inbox Repair Tool, make sure Outlook is updated to a fixed build:
   1. When Outlook is open (even in Safe Mode), select File > Office Account > Update Options > Update Now.
   2. Install any available updates and then restart Outlook.
4. If Outlook still will not open or keeps closing If the problem persists after disabling add-ins and updating, the cause may be a corrupted profile, damaged data file, antivirus integration, or another conflicting program. In that case, follow the broader troubleshooting in the “Outlook not responding error or Outlook freezes when you open a file or send mail” article, including:
   • Repairing Microsoft 365 programs.
   • Creating a new Outlook profile.
   • Checking antivirus integration with Outlook.
   • Using a Selective Startup (clean boot) to rule out other software conflicts.

References:

• I can’t start Microsoft Outlook or receive the error “Cannot start Microsoft Outlook. Cannot open the Outlook Window”
• Outlook not responding error or Outlook freezes when you open a file or send mail
• Something is wrong with one of your data files and Outlook needs to close
• Outlook Freezing and Not Responding and Not saving changes when ending the task - Microsoft Q&A
• Outlook won't open, says it coundn't open last time and asks if I want to open in Safemode - Microsoft Q&A
• What to do when Outlook will not open on my PC? - Microsoft Q&A
• New Outlook has stopped working, Fails when starting after 30 to 60 seconds - Microsoft Q&A
• Detected a problem launching new Outlook - Microsoft Q&A