To start Calibre in the system tray, normally you can execute the command:
When I do it, it always fails and opens in a normal window. Executing the above instruction in the terminal tells me:
Failed to create system tray icon, your desktop environment probably does not support the StatusNotifier spec
It would surprise me if this was really true, since I have other tray icons working like Teamviewer, Fl.ux, and Syncthing-GTK working in the tray.
I tried installing KDE and booting into it, and the problem was solved, but I don't plan on continuing to use KDE and Cinnamon side-by-side on the same OS install. Also, in my troubleshooting, I learned the devs recommend uninstalling the version of Calibre that is in the OS repositories and instead install the binary with a wget command from the Calibre website.
Is the calibre system tray icon really incompatible with the Cinnamon tray? If so, is there another tray I could install?