I upgraded to version 8 when it came out. My invitation events disappear from my calendar a few hours before the event itself, although they appear on my calendars in Version 7 (on a different computer), webmail calendar, Thunderbird, and my phone .
Customer support told me to try something that is impossible to do, and for two weeks I have tried to get more help. They are ignoring my repeated messages. I now have a calendar that doesn’t work and no way to get assistance.
If customer support is paying attention, please respond to my repeated messages.