So, I have faced this bug three times the last two months already.
During my sets, somewhere in the middle, the music stops, the waveform becomes blurry, the app remains functional, but for some reason, Traktor is not able to read any track from my collection. Although I can load tracks on the decks, their waveform is blurry and of course there is no sound. And this is happening with all of my (3) Music Drives, Traktor is not able to read any track from any drive.
I'm trying to reproduce the issue using the same track, but it's impossible. It seems completely random. I also tried to check the tracks for errors using mp3diags and mp3test, but there is no problem with the tracks according to these apps.