Hi. I've had this problem but I don't know how and why but I guess it sorted itself out. But this summer I had to format my PC and install traktor again. Before, I used to use VMS4 as my soundcard in traktor instead of ASIO from the amerIcan DJ (that one always made weird soundS in the music). I would choose external mixer and then choose and the channels 1,2,3,4.... and they're name were vms4 1, vms4 2 and so on. Now I inly have the option for 2 channels event though I have the controller chosen for 8 outs! Now I get the option of choosing the vms4 as my soundcard but it says its not conected. My vms4 has the dsp core so it's basicilly a vms4.1. So now I'm stuck with ASIO or ASIO4all and both of them make those weird cracks in the music.
Running windows 10, i7 8gbs ram