muscleclip conversion failed

I used “Robot Kyle” from unity3d.com to create a avatar, then apply to a animation clip, Console show “MuscleClip ‘JogForward_NtrlFaceFwd’ conversion failed: invalid avatar definition UnityEditor.DockArea:OnGUI()”.
Why???

Try pressing the Configure button in the Rig tab.

You should get a clear message of what is wrong.