Crazy Error

In the last event was a very strange problem (first time I saw it).
I was using two CDJ 2000 Nexus, DJM 2000 mixer, Macbooks and RB 4.2.4 with PRO LINK.
the left CDJ simply was "crazy." The sound was played correctly but the display does not espondia anything.
No buttons worked, it was not shown the waveform, playing time, no nothing. What worked was only the BPM number in the panel and was only showing the name of the last song played before the problem.
Could not even switch to playback via USB stick or memory card.
Only after turning off the CDJ and reconnect again it is that the issue is resolved.