Anyways, OneNote by default only allows one instance of the program at a time. This is fine, even helpful, except for the fact that either PlayOnLinux or Wine is not properly closing the ONENOTE.exe process when I close OneNote. I can type top in the terminal and see ONENOTE.exe among the listings. If I try to start OneNote, I get an error message saying there is still a OneNote session running, but if I kill the ONENOTE.exe process in the terminal, it works fine again. Killing the process will also bring up a PlayOnLinux error message saying that OneNote has crashed.

Disabling the toolbar notification does nothing. It seems like for some reason OneNote is trying to launch another process whenever I open it.