2] Convert the file If the above fix does not work, you can convert the file to the latest version of OneNote. Before proceeding, copy the notebook and paste it to another location to create a backup.

Tips If you work on both a PC and Mac, save your OneNote files to SkyDrive so that you can seamlessly transition from one operating system to the next.

Microsoft's OneNote app for Windows 10 will now allow the editing of attached files. The new ability is currently being rolled out to Office Insiders, and will come to more channels later.