A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
Hello,
Thank you for posting on Microsoft Community.
A quick question before we begin. Are you referring to OneNote App which comes with Windows 10 or the OneNote Desktop which comes with OneNote 2013?
This could be a sync conflict issue; to resolve this issue follow the step from the following Microsoft Article to reopen the Notebook which causes the conflict.
Check if the above steps help.
Thank you.