Why do the Cdj-2000 stop working sometimes when connected in HID mode with Traktor 2?

The last two nights,while djing at a local bar,the cdj 2000 stopped working whilst connected to my macbook pro and traktor 2.

Specifically,I was using the soundcard from the Djm-900 mixer and had connected the Cdj-2000 using them in advanced HID mode,when suddenly Traktor and the cdj's froze while the audio was still playing.

Turned off the cdj's and Traktor continued working fine,but when I them turned back on could not link them to Traktor.They did not give me the option to select deck or anything.

I would be extremly greatful if you could help me,because I'll be djing there regularly and I neex to fix this issue.

Note that everything is up to date,I am using a Macbook Pro and was using a usb hub with no external power.

Thank you in advance for your help.