A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
For OneNote on Android, the supported fixes in the available guidance are:
- Update OneNote from the Google Play Store, then restart the app.
- In Android, go to Settings > Accounts and check how the Microsoft personal account is listed.
- If the account is shown under Personal Account as a phone number, this is a known OneNote for Android sync issue.
- If the account is phone-number based, fully close OneNote by going to Settings > Applications > Application Manager > OneNote > Force Stop.
- Open OneNote again. If Account Error - Action Required appears, tap Add Email and add a valid email address to that Microsoft account. This is the documented workaround to restore syncing.
Important: if notes are currently unsynced, avoid uninstalling OneNote or replacing the device until syncing is restored, because unsynced changes are stored only on the device and can be lost.
If the notebook opens correctly in OneNote for the web, that points to the Android app as the problem device rather than the notebook itself. If the issue continues after the steps above, report it through Help > Feedback in OneNote, or post in the OneNote community forum.
The 404 problem for the support page is not covered by the available guidance, but the documented community path for OneNote for Android issues is the Microsoft Community / OneNote forums.