Third person AI error

Hi,

I am getting the following error even after I have deleted all of my AI character any idea how to fix this?

NullReferenceException: Object reference not set to an instance of an object UnityStandardAssets.Characters.Third Person.Character Control.Update () (at Assets/Standard Assets/Characters/ThirdPersonCharacter/Scripts/AICharacterControl.cs:29)

On a related note everytime I add a new AI character do I need to re-bake the navmesh?

Fixed I accidentally added the AI script to my sidewalk mesh…Oops.