Remove the message "This repetition is an exception to the event series"

Hi, I hope the translation for this message text is correct, as I am using the german translation of JEvents. Every month we have an event with different topics and speakers. I edited the single events of the series, but now it shows in the event details the mentioned message. How can I get rid of it without generating every event individually. I didn't find any configuration possibility in the control panel.

Thx for your help.

Alex