Hello back to you, thanks for the answer. This solved not my problem. But, thats okay. Well, then I have no other chance, and I will format my system today and change back to Debian Jessie. I don't install a foreign source on my system. I only install software from the main source of Debian. If I wanted to do that, then I could go to Ubuntu etc. But thanks for your answer and the attempt to help.
Friendly regards carlchen
