Okay, so this has driven me nuts since I bought my Komplete Kontrol S61. There are multiple things that cause the dreaded "failed to open komplete kontrol DAW-1"...
1st, Try just unplugging the stupid midi controller and plugging it back in (already mentioned)
2nd, double check your "sound" settings on your computer and make sure both your input and output are set to your interface ( I game with friends time to time and found that using external headphones will screw up the signals if I forget to change the setting back to my interface)
3rd, DON'T launch the Komplete Kontrol stand alone software before opening studio one. Open Studio one first! ( this one drove me nuts because I tried every techy thing under the sun before figuring out it was something so stupid)
4th, Try removing all your external devices and then re-adding them in Studio one.
5th, Make sure your audio interface software is updated (another dumb one I found out the hard way after using an old interface that had more inputs than my regular one)
I really hope this helps someone as I couldn't find much when I was searching... Good luck and happy mixing!