A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
Dear sAv119,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description, please don’t worry, we can work together to narrow down and resolve the situation.
First, to prevent the OneNote notes from losing, before doing any troubleshooting steps, I recommend backing up the affected notebook first.
If the issue only happens in a specific notebook, you may create a new notebook, copy and paste all notes in the new created notebook to see if it will sync normally.
Also, I suggest you go to OneNote Online, find the notebook, copy and paste all un-synced notebooks in OneNote Online, make sure they all appear in OneNote Online.
(I understand it will spend some time manually copying all un-synced notes to OneNote online, but this will reduce the risk of losing notes. Appreciate your understanding.)
If the error message still appears and notebook doesn't sync, since you have backed up the notebook in OneNote Online, try following:
1)Close the affected notebook in OneNote app.
2)Go to OneNote Online, open the notebook in browser first, then click Open in OneNote from ribbon to open it in OneNote desktop client app. See if the error message will disappear.
If above doesn't help, for further troubleshooting, could you please share information below?
1.Does the issue happens in all notebooks or just a specific notebook?
2.Where do you save notebook? Personal OneDrive or OneDrive for business?
3.Screenshot of error message encountered.
4.Which OneNote applications are you using? OneNote 2016 or OneNote Windows 10 app.
5.The version of your OneNote application.
Your understanding and patience will be highly appreciated. I hope that you are keeping safe and well!
Sincerely,
Waqas Muhammad
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