Rekordbox DJ Freezing

Hi guys! So I had a big problem in my last big gig! I have a mac book pro model 2016 and I had 2 cdjs2000 nexus, xdjrx, connected via USB cable to work with rekordbox dj, the program will freeze upon using it for 5 mins! Also the video plug in which I bought wouldn't work! I would play the music videos and they wouldn't show on the screens, all I got was a black screen! I have everything connected a power hub thru USB port, which I also had two hard drives. One other thing I notice is, if I try to use the internet while rekordbox dj is playing I start to get a weird echo type of effect which distorts the audio I just have to close the browser window then it goes away!! Someone please help me I can't keep letting this happen in my live leagues!! Thanks!