Cannot add an event to Google Calendar
I switched from Safari to Firefox (57.0.4) on my iMac (El Capitan) and noticed that I cannot add an event to my Google Calendar. Before, I was able to do so by clicking on a date. I tried both double-clicking and right-clicking but nothing happens. Also, clicking on the "+" sign which says "Create" does not work. The three-bar menu on the left corner does not work as well.