A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
Dear Devan Lejnieks
Thanks for raising your concerns in Microsoft Community.
Based on your description, I understand that you cannot view old notebooks in your account. I understand your confusion.
The code you attached should be the data ID of the note file. After opening the note in OneNote.com, the ID will be displayed in the URL link. Therefore, if the ID appears on the error message interface, it should only be used to refer to the notebook.
Since your question is posted in the iPhone or iPad section, did you open the notebook in the OneNote app on iPad or iPhone? Is there an error message? To help us understand the specific situation of the problem more clearly, can you take a screenshot and share it with us through a reply?
And you can also visit OneNote.com directly to see if the note can be opened smoothly. This is to confirm whether the note file is damaged and whether the problem is related to the OneNote app.
Please refer to the above information for testing and share the latest progress with us through a reply. Thank you for your understanding and cooperation.
We are looking forward to hearing from you and will continue to assist you.
Best Regards,
Tracy - MSFT | Microsoft Community Support Specialist