How to fix missing add-in on Outlook 2019, 2016, 2013, 2010 or Office 365

If you’re encountering missing add-ins in Outlook 2019, 2016, 2013, 2010, or Office 365, here are some steps you can take to troubleshoot and fix the issue:

1. Restart Outlook: Sometimes, simply restarting Outlook can resolve add-in issues.
2. Check Disabled Add-ins: Outlook might disable add-ins if it perceives them as causing issues. To check for disabled add-ins:
   • In Outlook, go to “File” > “Options” > “Add-Ins”.
   • Look for disabled add-ins in the “Disabled Application Add-ins” list.
   • If you find your add-in listed there, select it, then click “Enable”.
3. Check COM Add-ins: Add-ins might be listed under COM Add-ins. To check:
   • In Outlook, go to “File” > “Options” > “Add-Ins”.
   • Select “COM Add-ins” from the drop-down menu next to “Manage” at the bottom.
   • Click “Go…”.
   • Check if your add-in is listed and enabled. If not, select it and click “OK” or “Enable”.
4. Update or Reinstall Add-ins: Ensure that your add-ins are up-to-date. Visit the website of the add-in provider to check for updates. If there are no updates available, try reinstalling the add-in.
5. Check Antivirus or Firewall: Sometimes, antivirus software or firewall settings can interfere with Outlook add-ins. Temporarily disable your antivirus or firewall and see if the add-ins reappear. If they do, you may need to adjust the settings to allow the add-ins.
6. Repair Microsoft Office: If none of the above steps work, you can try repairing your Microsoft Office installation:
   • Go to “Control Panel” > “Programs” > “Programs and Features”.
   • Right-click on “Microsoft Office” and select “Change”.
   • Choose “Repair” and follow the prompts to repair the Office installation.
7. Check Group Policy Settings: In a corporate environment, group policy settings might restrict the use of certain add-ins. Contact your IT department to ensure there are no such restrictions in place.
8. Check Event Viewer for Errors: Sometimes, errors related to add-ins might be logged in the Event Viewer. Check the Event Viewer for any relevant error messages and troubleshoot accordingly.
9. Contact Add-in Support: If you’re still unable to resolve the issue, reach out to the support team of the add-in provider for further assistance.

You can also configure Outlook to never disable add-ins if you always need them enabled.