Hi
AT&&77,
Sorry about the inconvenience.
The OneNote syncing mechanism is different from OneDrive sync client, although your notebooks are stored in OneDrive cloud storage, the syncing procedure is performed inside of the OneNote Desktop
client, not your OneDrive.
In your scenario, I have some suggestions to narrow down on this issue:
1.Go to the OneNote Online, sign in your Office 365 work account, check if your notebooks could be opened without issue.
2.If you have confirmed the Notebook can be opened via OneNote Online without issue, please export your current notebook to the local drive as a backup, and click on
Open in OneNote in the OneNote Online web page. This should open the notebook in your desktop client, and check if the notebook could be synced normally.
3.Log out your account in the OneNote 2016 desktop client and log in again.
4.Is the sync error occurring on all of your notebooks or just a specific one? Please try creating a new notebook via OneNote 2016 and store it in the OneDrive, check if the sync error persist.
Please let us know the result.
Regards,
Alex Chen