One note closing

For OneNote on iOS, try these steps in order:

1. Force close OneNote and restart the iPhone or iPad. This can clear a stuck app process.
2. Check whether it happens with one notebook or all notebooks. If it is only one notebook, that points to a notebook-specific sync or content issue.
3. Make sure notes are fully synced before more disruptive steps. Verify recent changes appear in OneNote for the web or on another device.
4. Close unused notebooks, then restart OneNote. Closing cloud notebooks removes the local cached copy after restart. Do this only after confirming the notebook is fully synced.
5. If a notebook seems stuck, close and reopen it. Closing and reopening can reset the sync connection between OneNote and the service.
6. If the problem continues, delete and reinstall OneNote only after confirming notes are safe on another synced device or in OneNote for the web.

Important: before closing notebooks or reinstalling the app, make sure unsynced recent notes are backed up. Closing a notebook that is not fully synced can leave recent changes only on the device.

There is also a reported iPad white-screen issue that was resolved by updating iOS, so installing the latest available iOS update is worth checking.

References:

• Manage notebook storage in OneNote | Microsoft Support
• [Windows
• OneNote won’t sync - Microsoft Q&A
• White screen when returning to ONE Note on my IPAD - Microsoft Q&A