Hi Klaus69!
Fist of all sorry for my late answer I was not next to internet connection. Second thanks for your answer. I wouldn’t like to downgrade my shop so I already contacted them on an other site and I got this answer:
“As for your problem, my advice is to wait a little bit, until the next release, because will contain fixes for some of the problems. Is a matter of days. After that, if you will stil have the problem contact your theme author, or just wait a litle bit more to give them time to adapt the theme to the new woocommerce release.”
So I will contact my theme author(again) and let’s see what will happen. ??