OneNote Gem Add-Ins

Question:

I haven't opened Mac OneNote in a long time, and when I open it today, I'm asked to sign in to my account again. So, click Sign in to my account.
Enter the username, the password. OneNote pops up tip:
 
The authentication session has expired. Please sign-in again.
 
Enter username, password multiple times, it still pop up this dialog box. How do I fix it?
 

Solution:

1. Open Mac 'Keychain app'.
2. Select your default keychain on the left side, this is usually the 'login' keychain.
3. Search the “Office”
4. Delete all items in list.
5. Finally, restart Mac system.