Function Not Supported on AnimationEvent

I have an animation event to add a footstep sound for my running animation, but I can’t get the sound to actually play.

public class FootstepAudio : MonoBehaviour {
	
	public AudioSource footsteps;
	public Animator anim;
	AnimationEvent footstepsEvent;
	
	// Use this for initialization
	void Start () {
		
	}
	
	public void PlayFootsteps (){
		Debug.Log ("Playing footstep sound!");
		audio.Play ();
		
		print (audio.clip.name);
			
	}
}

I have an AudioSource on the same GameObject as this script set up to play the footstep sound. In my Animation window, I have one event set up to play a footstep sound on a footfall. When I try to edit that event, it says Function Not Supported in the drop down beside this script.

The Debug.Log executes, so I know this function is being executed. I just have no idea what’s wrong with it.

It’s a bug with Unity’s animation window.
If your functions are being called, then you’re all good, and you can ignore the “Function not supported” messages.

The bug is that this “Function not supported” message displays for any function that does not belong to the very first script you added to the game object. However, the functionality of calling the function is not affected.

Here’s a forum thread to backup what I’m saying:
http://forum.unity3d.com/threads/animation-editor-function-not-supported.35481/