Replace A Component Then Crashes

Using Unity 4.2.1f4. Whenever I add my script which requires a Character Controller but when I add the script Unity ask to replace the current collider, I click add or replace and it crashes. Am I doing something wrong? I am new to Unity. Here my MovementController script:

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent (typeof(CharacterController))]
 [RequireComponent (typeof(Animation))]
 [RequireComponent (typeof(PlayerInput))]
 public class MovementController : MonoBehaviour {
     
     public enum State {
         Idle,
         Init,
         Setup,
         Run
     }
     
     public enum Rotate {
         left = -1,
         none = 0,
         right = 1
     }
     
     public enum Move {
         backward = -1,
         none = 0,
         forward = 1
     }
 
     private Transform myTransform;
     private CharacterController myController;
     private Vector3 myDirection;
     private CollisionFlags myCollisionFlags;
     
     public float RotationSpeed = 100;
     public float MovementSpeed = 5;
     public float StrafeSpeed = 3;
     public float Gravity = 20;
     public float AirTime = 0;
     public float FallTime = 0.5f;
     public float JumpHeight = 8;
     public float JumpTime = 1.5f;
     
     public AnimationClip RotateAnimation;
     public AnimationClip MoveAnimation;
     public AnimationClip StrafeAnimation;
     public AnimationClip JumpAnimation;
     public AnimationClip FallAnimation;
     
     public bool Jump;
     
     private Rotate rotate;
     private Move move;
     private Rotate strafe;
     private State state;
     
     
     void Awake() {
         myTransform = transform;
         myController = GetComponent<CharacterController>();
         
         state = State.Init;
     }
     
     IEnumerator Start () {
         while(true) {
             switch(state) {
             case State.Init:
                 Init();
                 break;
             case State.Setup:
                 Setup();
                 break;
             case State.Run:
                 ActionPicker();
                 break;
             }
             yield return null;
         }
     }
     
     void Init() {
         if(!GetComponent<CharacterController>()) return;
         if(!GetComponent<Animation>()) return;
         
         state = State.Setup;
     }
     
     void Setup() {
         myDirection = Vector3.zero;
         rotate = Rotate.none;
         move = Move.none;
         strafe = Rotate.none;
         Jump = false;
         
         state = State.Run;
     }
     
     void ActionPicker() {
         if(rotate != Rotate.none) {
             myTransform.Rotate(0, (int)rotate * Time.deltaTime * RotationSpeed, 0);
             Rotating();
         }
         if(myController.isGrounded) {
             AirTime = 0;
             
             myDirection = new Vector3((int)strafe, 0, (int)move);
             myDirection = myTransform.TransformDirection(myDirection).normalized;
             myDirection *= MovementSpeed;
             if(move != Move.none) {
                 Moving();
             }else if(strafe != Rotate.none) {
                 Strafing();
             }else{
                 Idle();
             }
             if(Jump) {
                 if(AirTime < JumpTime) {
                     myDirection.y += JumpHeight;
                     Jumping();
                     Jump = false;
                 }
             }
         }else{
             if((myCollisionFlags & CollisionFlags.CollidedBelow) == 0) {
                 AirTime += Time.deltaTime;
                 
                 if(AirTime > FallTime) {
                     Falling();
                 }
             }
         }
         
         myDirection.y -= Gravity * Time.deltaTime;
         myCollisionFlags = myController.Move(myDirection * Time.deltaTime);
     }
     
     void MoveAction(Move z) {
         move = z;
     }
     
     void RotateAction(Rotate y) {
         rotate = y;
     }
     
     void StrafeAction(Rotate x) {
         strafe = x;
     }
     
     void JumpAction() {
         Jump = true;
     }
     
     void Rotating() {
         
     }
     
     void Moving() {
         
     }
     
     void Strafing() {
         
     }
     
     void Jumping() {
         
     }
     
     void Falling() {
         
     }
     
     void Idle() {
         
     }
     
 }