The Lighting Controller

I have been using Showxpress for the last several months without any issues, but today I am unable to get the DMX control button to turn from red to green.
I am running v.6.332 on a Mac Mini running v.10.8.2 to a Xpress-512plus

Here is what I have tried:
The Xpress-512Plus shows a link to the PC.
The light show is loaded.
When I start the Editor or Live I can not get control of the lights.
When I click the DMX button it remains red.
I've restarted the system.
I've tried reloading the light show.
I've made sure that the firewall was off.
I have tried installing a previous version of Showxpress with the same results.
I have restarted my DMX distributor without any change.

Not sure what to do next. Any Suggestions?

So far, we know only two things which blocks network com: firewall and antivirus (viewtopic.php?f=3&t=1955).
If this is not the firewall, it should be the antivirus.

PS: first time we hear this problem on MacOS !