Hey,
thanks guys. I already know this horseman, but even thank you for helping.
Its just exactly like you wrote it cheesecake. I wasnt able to check the stage control indication to this point of time, but I already uploaded the .craft file.
https://www.file-upload.net/download-13246064/Beyond.craft.html
Maybe, I fortgot some information. After decoupling the "middle" stage, I have to change the vehicle, which is controlled, by using the map. Maybe KSP recognizes the top stage, as an independant spacecraft.
Thank you