Rekordbox DJ suddenly terminates

Hey Guys,

Last night i had a strange issue. My Rekordbox DJ suddenly cradhed during the set and i dont know why. I had no audio dropouts or somethin similar, the application just closed itself and i could restart it right away and it worked perfect the rest of the night.

My setup:
Rekordbox DVS (latesz version) used with turntables and control vinyls
MacBook Pro
Pioneer DJM S9
Pioneer DDJ XP1 Controller

So what do you think could be the issue?

Kind regards
Tom