A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
Thank you for letting me know.
That error usually points to a sync location problem, account permission issue, or OneDrive storage/account issue.
Since you can see the notes online, please do not delete anything yet.
In the meantime, if you haven’t already, please check these first:
- Open OneNote online and confirm you can open the notebook there.
- Try creating a new notebook from OneNote online.
- Check your OneDrive storage here: https://onedrive.live.com/?v=managestorage
- On the iPad, make sure OneNote is signed in with the same Microsoft account used online.
- Update OneNote from the App Store, then restart the iPad.
- If the notes are safe online, sign out of OneNote on the iPad, then sign back in.
If the issue only happens on the iPad, it is most likely the OneNote app cache or sign-in token. Reinstalling OneNote can help, but only after confirming the notebooks are accessible online.