The "casparcg.config.ini" is created by the Installation and after renaming nothing happened.
after some time i noticed the original "casparcg.config" is loaded instead of the one next to the plycast.exe. 
I tryed to edit "PlyCast/casparcg.config.ini" instead of "PlyCast/ext/casparcg/casparcg.config"
Thanks for the help.