I just stumbled upon the fact that Native Instruments' Maschine and/or Komplete Kontrol plugins won't show up as expected when used in your DAW as a plugin directly. The browser window did not appear and for Mschine it's essential to choose your kit or instrument to work with. Other to when using those programs as stand-alone versions the browser might not show up. But it's easy to bring them up: go to the menu, choose "View, Browser" and they will appear.