Onenote is cleaning up

[math0ne]

After I install this I get this message when trying to open onenote and it doesn't open. After a restart it goes away and works fine. Any way to avoid this? Testing changes is very slow with having to restart every time.

[andreismolingmail]

The issue is seemingly caused by another instance of ONENOTE.EXE hanging in processes. Closing OneNote UI after I click the Ribbon button doesn't finish that process and I get the message above. Killing that process or restarting the machine helps. Still, the issue should be solved.