Do you see any errors reported in Tools > Error Console? If yes please copy and paste them here. In a 2nd test you could set the advanced preferences "calendar.debug.log" or "calendar.debug.log.verbose" or both to true and check the Error Console for more verbose information.
Do you see any errors reported in Tools > Error Console? If yes please copy and paste them here. In a 2nd test you could set the advanced preferences "calendar. debug.log" or "calendar. debug.log. verbose" or both to true and check the Error Console for more verbose information.