Thank your for your answer. That's what I thought.
But now I have another problem.
I'm set a RecurrenceRule to an appointment (daily for 10 days) and add for day 4 an AppointmentException.
The problem is, that the Scheduler display at this day 2 appointments now. The appointment from the Exception and the appointment from the rule, which should not be shown.
Can you tell me, what I'm doing wrong?