DDJ-SZ + Mac el Capitán + Serato DJ + S-DJ50X-w: No output Master

I finally got a DDJ-SZ and i cant get any audio from master even with there's green lights in the master level.

I just recorded a video about this:

https://youtu.be/gS1L4Ke-HjQ

As you can see, i got 2 S-DJ50X-w (only one powered plugged), connected via Master Output using XLR but nothing comes out =(, only in headphones.

Any suggestions? 

Thanks in advance