Most likely because of your audio pref setup. Check all audio preferences (first check if there is a signal in the mixer, and on what bus the signal is on the mixer). Then check in the audio preferences if this bus is set to the AES/EBU out you want to use, and if AES is turned on. What do you use to monitor the AES/EBU signal? Are you sure the connection is okay?
Thanks Floh. Actually the audio just quit as I was about to master. Then nothing out. I took the output of my digibeta into the flying cow and heard audio. Used the same cable and plugged it directly into the breakout box. Nothing. That eliminated the cable and flying cow. I ran the audio hardware test and it failed with numerous errors.
At that point I powered everything down and reseated the boards. Fired it back up and it works all of a sudden. odd.
Apparently what started this was me pulling an SDI video output while the software was running. I was changing to a guest deck. I actually did it again and heard the audio drop out and I could not get it back. The software would not reboot. I kept getting an error that said the genesis engine was "busy" cannot start program.
The remedy was to pull the AC power plug from the computer for a couple of minutes and let the boards reset. It works fine now.