AnimatorOverrideController not overriding

Hey,
I'm using a tutorial i found on youtude to make an rpg and everything is going fine except i cannot get AnimatorOverrideController to work as described. I think i have a version problem, but I cant really find anything useful or a useful solution, so I figure I must be doing it wrong. The example code from the unity site is nearly identical, but it doesnt work either!

animatorOverrideController = new AnimatorOverrideController(animator.runtimeAnimatorController);
throws an error. does not contain a 1 arg constructor.

I know what the error means, but when i remove the arg and use

animatorOverrideController = animator.runtimeAnimatorController;

in an attempt to resolve the missing arg, it doesnt override. Please help b4 I get frustrated and give up!