I have this problem with several OneNote Notebooks, online.
I'm accessing Office 365 on a university server. I created a OneNote Notebook called notebook1.
I then open OneDrive online, and delete notebook1. The Notebook file no longer exists.
Now, when I open OneNote Online, it lists notebook1 as being available, even though the file is gone.
If I click on the file to open it, I get a web error.
I would like to remove the orphaned file from the list.
Or, start over again, with an empty OneNote Online install?