I am the developer of Animatron Player.
It's important that
attachedTo is not a static method of
anm.Player, so you may call
player1.attachedTo(WRAPPER_ID1) and this code should work.
Though, I think, the Player shouldn't already be there in your case (and that's what it complains about, with this error message), unless I'm not getting the point. As I get from functions and variables names, you have several Players and several animations. Please ensure
startAnimation1 is not creating a new Player, but only starts the animation using the prepared existing one.