I am running this on my iMac Retina at the moment, couldn't wait to try out photos.app. That said, I understand it is a beta, I just want to see if this is common before I spend much time trying to correct it. Since I updated I have lost audio from any internal speakers, or the headphone jack. They are not even listed as devices in settings. My USB Dac is working fine. I have tried rebooting without it hooked in, which results in no audio devices at all to select from. Anyone else having this issue on the beta? I ask because I have not heard of anyone else running into this.