Two or three weeks ago, Youtube stopped working for me. I now get a message in the video frame that says: "Your browser does not currently recognize any of the video formats available."

Prior to this, I used to get the same message briefly, but then it would change to the HTML5 icon, and then it would play. But now it just hangs on the error message and nothing happens. I had been using Safari 9.somthing. I have now updated to 10.1, thinking it would fix the problem, but I'm still getting the same message, and the videos still don't play. Any ideas?

BTW, Firefox works just fine on Youtube.


MacBook Pro 15" (2015)
Sierra 10.12.6