Roon wouldn't play

I had a problem last night around 7pm eastern time. Everything seemed to be working well, but nothing would play. I tried playing genre radio and local files. I’d click play, then play again on the black screen (or radio), and the clock would sit at zero–it wouldn’t advance. I tried restarting Roon several times with the same result. Fine this morning.

I also noticed that my default setup with my Explorer2, disappeared around the same time; I had to set it up again.