cintiq 21ux tablet issues.

I recently updated yosemite's download update and my computer froze. I sourced to the cintiq 21 ux which was working fine prior. Any idea to get my tablet working again?? the tabelt has a usb and dvi (thunderbolt converter I used) and when I plug back onto the computer it freezes and blacks out my main thunderbolt screen. I tried uninstall and reinstall the driver for the tablet but still doesnt work... help..