No audio, coreaudiod not running on MB Air
I'm trying to get the audio working on an Air running MacOS10.12. No sound through either headphones or internal speakers although System Preferences recognizes when the headphones are plugged in and shows internal speakers under output when no headphones connected. All of the sound controls are grayed out. The owner of the Air has Avast anti-virus running and has FileVault enabled, if that makes any difference.
I noticed that coreaudiod is not running and have been unable to get in to start. I've tried resetting NVRAM and SMC a few times. I tried starting in Safe Mode. I've tried inserting and removing the headphones several times. Nothing works.
Suggestions?
MacBook Pro with Retina display, OS X Yosemite (10.10.2)