My problem is that
.ics attachments from E-Mails, which I open in GMail.com, are not saved in Google Calendar, although I press "Safe". More specifically, the appointment is saved but disappears on reload.
The attached picture shows that everything looks normal when I use GMail's dialogue to import an
.ics into the calendar (Notice the orange bar on top, which - in German - states that the
.ics has successfully been imported):
However, when I reload the calendar, it looks like
I'm using FF 36.0.1 on Ubuntu 14.04, but I failed on a Windows 7 Machine as well. Cookies are allowed (if that matters). I also tried to change the calendar entry somehow (i.e. another time or date), but without positive effect.