User can’t open individual calendars of the member in the group calendar. He can however open their individual calenders through his mailfile (Calendar - open another person’s calendar).
When he clicks a row in the group calendar to see that person’s events are he gets the error: “Unable to open user’s mail database”
Why is that - shouldn´t he have the necessary rigths since he can open them from his mailfile?
Can anyone please explain to me how group calendars works and tell me what to do with this? 
Please help me!