Hey!
Following Steps worked out good:
Downloading the ASIO4All driver and installing it.
Starting the 32bit version and choosing this driver in the interface section of the program
Closing the 32bit version
Opening the 64bit version (wich has opend then with ASIO4All)
Choosing the originally wanted driver in the interface section
Even a restart of the 64bit version with the focusrite ASIO driver configuered then was successful.
Lots of lots of thanks for your help.
Maybe this helps others too.
Greetings