HELP NEEDED! Sonar X2a crashed and no audio playback anymore

I purchased X2 (and installed the X2a patch) two days ago and was enjoying it but using the quantize function on midi resulted in a bad crash. I had to reboot my computer about four times to allow X2 to load the project without removing all the audio devices. Finally, it loaded the audio devices and I can see them in the preferences but I no longer have any audio output. X1 does work so I'm not in a dire situation, but am slightly surprised by such a destructive crash a day or two into normal use of the program. Any ideas how to get audio play back to resume in X2a? I don't know what to do other than go through the very long uninstall/reinstall process and hopefully there is an alternative fix?? Thanks.

Sometimes when Sonar crashes, you'll need to power your AI down then restart your puter. You may not need to restart the puter but almost always, you'll have to restart your AI.

AI (audio interface)

Listing some of your specs might help get to root of problem.
 
It may seem a silly question, but did you check that your Master Bus fader was not set to zero?
 
Quantizing MIDI here works okay, so there must be a solution for you.

EDIT - Ok, I found a solution. In the Sonar x2 producer folder, I removed the AUD file (backed it up first). When restarting Sonar x2, it recreated the AUD file and audio is now working! :-D so it must have gotten corrupt when Sonar X2 crashed. Thanks.