If you are using a batch file, it's easy to stop and see what the error is.
Add a pause on the second line of your batch file, like this:
Kangaroo.exe -t 0 -d 12 -gpu -g 20,256... etc.
pause
I don't know how to set a proper command in the batch file, what do use yourself, could you give me the whole correct command? I will change my specifics to meet my system config, thank you. Also isn't this kangaroo used to find addresses with known public keys? If that's the case and there are no more public keys left in the puzzle challenge, I don't want to use it, not interested in cracking keys which are not mine.