When HDMI is plugged in Mac

I have ios 10.8 on McBook Pro. Until few days ago I had Yosemite. I started using Roon in December and I am very happy with it. However, a few days ago, on Yosemite and now on 10.8 with Roon 1.3 I have the same problem: I have to have HDMI connected to my Mac. It was like that from the beginning and it is OK. Now, when I start Roon, I get No Audio Device Found. When I take out HDMI, Roon can see my Zone. When I plug HDMI back, again I get No Audio Device Found. And I cannot see my device in settings, only NETWORKED part.
My Mac is connected to m2Tech Hiface Evo, but it was working fine. As I said, HDMI must be connected. But regardless of that, it was working fine for two monte, and now…!?
Thank you

Can you upgrade to a later version of macOS? Eg. Sierra (10.12)?
Did you have installed all the latest updates of Apple?

Have you enabled the Build-in output in the Audio Setup part in Roon?

Can you else help us with screenshots what you see on the Audio Setup page when you have the HDMI plugged in and what you see when you have it disconnected?

Today Roon asked me to do upgrade, which I did, and now it works again. No idea what happened as long it is OK :sunny:
Some strong clicks and pops I can hear now though. Will surch the community to see what to do.