Hey guys,
sure, I´m sorry. Now I got it:)
i got one more question: In the data is a second object. I made a cut with b. diff. with an freeform curve. Now i made a new surface with network to get a solid again. I´d like to b. union the surface and the cut object, but it does not work. I think this is a real nooby question;)

Thank you guys so much!