
Have you update your NXS2's firmware to the latest one?
In addition, you need to install a AGGREGATOR tool on your computer following the install guide.
http://www.pioneerdj.com/en-us/support/software/cdj-2000nxs2/#firmware-update
http://www.pioneerdj.com/en-us/support/software/djm-900nxs2/#firmware-update