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Can you access these notebooks on OneNote online? I suggest you sign into your account to have a check.
- If so, please click File > Info > Edit in Desktop App. You may also share them to other people, and download them for you.
- If not, it's recommended to go to this shared drive to check whether there are you notebooks directly. Please ensure you have enough permission on this shared drive.
Besides, please locate to File > Options > Save & Backup, find the Backup Folder. Such as C:\Users\Windows account name\AppData\Local\Microsoft\OneNote\16.0\Backup.
Then to to this folder, try to find the corresponding backup files for your notebooks.
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