Squeezebox starts to play a selected cut, then stops after a few seconds

Here's the part that I don't get. It used to work perfectly, and did so for years. I'm running OS X 10.11.6 (El Capitan) and Logitech Server 7.9.1 Build rt517314665 1/28/2018. Problem does not occur when listening to Internet radio stations. That works as always.

HELP! Anyone have any ideas?

Thanks

George