Hi Anna
I use a Kontrol S4mk II so we should be able to see the same things. Dont panic their is a few more things to try before a new install. So before you go and start again try these.
Where you see the clock at the top, just to your left do you get any feedback from the “CTRL” indicator when you move any of the buttons/knobs on your S2? It will light up when you move somin.
Import the .tsi you get from NI for your S2 (not your saved one) that should have the basic settings to get the S2 up and running. Make sure its in external mode in the “output Routing” in preferences as your using the S2 to kontrol the software. Also make sure you have selected the NI Kontroler S2 in the “Audio setup” in the preferences box.
The link below is an image of the preferences box, copy the link into your browser and it will take you to Dropbox. You dont have to sign up to it you can view the image on the screen. Its an image of the preferences box with a red arrow next to the “setup wizard” This is what you press to start again. Dont do this yet tho as we have a few things to try.
https://www.dropbox.com/s/spvqhe2qukh58yy/ScreenHunter_02%20Aug.%2009%2015.16.gif?dl=0
You could reinstall Traktor but if it happens again you’ll be back to square 1 and not know what the issue was.
Dave.