If you are having persistent difficulty closing your Microsoft OneNote  books please follow these steps.

Note

- this option should be used only after trying to manually close your OneNote  book and after trying the basic troubleshooting techniques that can be found here.

1. Open Finder .
2. Select Go from the top left-hand Menu Bar.
   
   
    
3. Hold the Option key on your keyboard and then select Library.
4. Enter "com.microsoft.onenote.mac"into the search bar on the top right of Finder , and select Search: "Library"​.
   
   
5. Select all Files/Folders that contain "com.microsoft.onenote.mac" in their name and move them to Trash.
   
   
    
6. Restart your machine. You should now be able to open and close Microsoft OneNote   successfully. If the problem persists please visit 1Degree.