my participent can't start Zoomvwith my ID, because an error "falscher Kenncode" appears.

Hey @voc_de_de seeing that you are getting an error for a wrong meeting passcode? If so, please check your upcoming meeting https://zoom.us/meeting#/upcoming to ensure that the participants have the correct passcode for the meeting that is scheduled or when scheduling. 

Secondly, you have the ability to Embed the meeting passcode in invite link. The meeting passcode will be encrypted and included in your invite link to allow participants to join with just one click and avoid having to manually enter a passcode. An embedded passcode makes your meeting more secure and easier for attendees to join.

If you prefer to disable Embed passcode in invite link for one-click join, your attendees will have to manually enter the meeting’s passcode.