Of late, users of Microsoft OneNote have been experiencing sync issue with the software giant's cloud storage service OneDrive. Now, the company has officially confirmed the issue, saying that the root cause has been identified and they are working on a fix. The issue is that OneNote has stopped syncing to OneDrive, giving errors like We can't complete this task. Try again or You don't have permission to edit this file and the sync has stopped. Contact the owner. "The service side interruption started impacting customers sometime week of April 10, 2017 and may impact other Office Mobile...
Source: http://www.gsmarena.com/microsoft_acknowledges_onedrive_sync_issue_says_working_on_a_fix-news-24594.php