OneNote Gem Add-Ins

UWP: Couldn’t open the notes. OneNote may still be syncing them, not have permission to open them, or they may have been moved or deleted

More Notebooks -> Choose notebooks to pen

When click “More Notebooks …” enter “Choose notebooks to open” window, then choose a notebook to open.
 

More Notebooks -> Choose notebooks to pen


Couldn’t Open the Notes

Because OneNote for Windows 10 doesn't indicate which notebook has been deleted in the notebook list. When you click to open a notebook, it is possible to display:
 

Microsoft OneNote
Sorry, we couldn’t open the notes that you were looking for. OneNote may still be syncing them, you may not have permission to open them, or they may have been moved or deleted.

 
This bothers you a lot. You simply don't know which notebook has been deleted.

Sorry, we couldn’t open the notes that you were looking for. OneNote may still be syncing them, you may not have permission to open them, or they may have been moved or deleted.


“Open Notebook” Menu Item of Gem Menu

You can identify which notebooks have been deleted by the "Open Notebook" menu item in the Gem Menu for OneNote UWP.
In Gem Menu click “Gem“ menu -> Open ->  “Open Notebook“ menu item.

“Open Notebook” Menu Item of Gem Menu

Deleted Notebook

In the list of OneNote Online Notebooks that pops up:
The notebooks with red icons have been deleted.
 
When you right-click the notebook, a right-click menu will pop up, and you can click "Information" to view the notebook information.
Notebook State: Deleted Notebook
 
Notebook State: Deleted Notebook

Download Gem Menu for OneNote UWP