Yawgmoth, Thran Physician sacrificed itself
I tried to use its ability during a slow and grindy match , mtgo was sluggish, but it sacced to itself. That is a bug, it should only allow to sacrifice another creature as i intended anyways.
So it sacrificed my creature that says , sacrifice "another" creature. Itself should not happen since its not a legal game process.
just happened to me!