Reinstall add in

In some cases, macOS requires you to reinstall the addin: 

1. Hold the "Option"- key and click on the empower sync icon to reinstall the add in.
   
2. Restart PowerPoint
3. Click on the "Tools" tab and navigate to "PowerPoint Add-Ins"
   
   
    
4. Check if the "empower-slides" checkbox is checked, if not check and confirm it by pressing "Ok".
   
5. Close PowerPoint.