This is a completely different computer. It was working fine until very recently when I opened Premiere and got a prompt saying "Your audio device no longer works." So I looked at the audio hardware like the above forum:
The screen shot was taken before I changed it, so I did change it on this different computer to NO INPUT but it still does not work. I didn't re-boot or anything like that. When I export the timeline and play the video, the MP4 does play fine, both video and audio. I just cannot hear it on the timeline. So I'm not sure what to do to get this to work again.