That's a bummer. I have been re-visiting "Night Court" episiodes lately thanks to the LAFF rerun channel. It was one of my favorite shows growing up, and he was part of the glue that held it together.
Anyone wanting to see a different side of Mr. Robinson, check out the gloriously tasteless '70s blaxploitation flick "The Black Gestapo," in which he plays the leader of a Nazi-esque gang of L.A. street thugs! The first time I saw that, I said "Oh, my! Mac, Judge Stone would never approve of this."
R.I.P. sir.