Rekordbox does not recognize CDJ 2000

if you are on a pc and installed RB again, you will ave to ad the exceptions again most likely. Try disabling wireless, firewall and any antivirus to test

If you are using a firewall, if  you upgrade the software it's VERY likely that the firewall will not allow the new software to connect as it is in a different location than the previous version and it will be treated as a different program.  You either need to reconfigure the firewall to allow it through or turn off the firewall altogether.

Not sure if this is a mountain lion issue or just something wrong with set up. I recently updated to mountain lion and lost everything. I reinstalled everything but now when I go to link everything together (900 nexus & 2 cdj 2000s) my mixer appears but not the cd players. I adjust the firewall, the network settings, and everything else suggested by pioneer and have not found any useful threads anywhere. Please any help would be greatly appreciated! 

@DJ TEBBZ - do you turn your W--Fi off? Mine will only link when I turn my wireless card off.

Yea, I had that issue when I first bought my cdj's but fixed in since then and tried playing with all of that again to see if it would make a difference and no luck. Even when I connect the line directly to my mac. And FYI if you go into network settings and click set service order and put the ethernet connection on top you shouldn't have that issue anymore. 

@DJ Tebbz > Can you ensure your players are on the latest firmware, drivers installed and using the most recent version of rekordbox (1.6.2) please.

Disable any anti-virus software or firewalls you have may running. Also, you may have to disable WiFi.

What hardware are you using to Link everything together?