What could be freezing unity?

Hi, in my game you are supposed to play as a vampire, and I am adding the mechanic to morph into a bat for short periods of time, however, something is causing unity to freeze. The objective is simple in the script, there is one script that controls movement, and another script that controls the Player state (bat or vampire), but when I press the key to do it, unity freezes.

Movement Script:

 using UnityEngine;
 using System.Collections;
 
 public class VampireControllerScript : MonoBehaviour {
 
     CharacterController controller;
     bool morphed = false;
 
     float speed;
     public float flySpeed = 8.0F;
     public float runSpeed = 6.0F;
     public float walkSpeed = 3.0F;
     public float jumpSpeed = 8.0F;
     public float gravity = 20.0F;
     private Vector3 moveDirection = Vector3.zero;
 
     bool walking;
 
     public CameraTargetScript cameraTargetScript;
 
     void Start () {
         controller = GetComponent<CharacterController>();
     }
 
     void Update() {
         if (!morphed){
             if (Input.GetButton("Sneak")) {
                 if (controller.isGrounded) {
                     walking = true;
                 }
                 else {
                     walking = false;
                 }
             }
             else {
                 walking = false;
             }
 
             if (walking)
                 speed =  walkSpeed;
             else
                 speed = runSpeed;
             
             if (controller.isGrounded) {
                 moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
                 moveDirection = transform.TransformDirection(moveDirection);
                 moveDirection *= speed;
 
             if (Input.GetButton("Jump"))
                 moveDirection.y = jumpSpeed;
                 
             }
 
             moveDirection.y -= gravity * Time.deltaTime;
             controller.Move(moveDirection * Time.deltaTime);
         }
         else {
             moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
             moveDirection = transform.TransformDirection(moveDirection);
             moveDirection *= flySpeed;
             
             if (Input.GetButton("Jump"))
                 moveDirection.y = jumpSpeed;
             
             
             controller.Move(moveDirection * Time.deltaTime);
         }
     }
 
     void LateUpdate () {
         if (!morphed)
             transform.rotation = Quaternion.Euler (0f, cameraTargetScript.currentYRotation, 0f);
         else
             transform.rotation = Quaternion.Euler (cameraTargetScript.currentXRotation, cameraTargetScript.currentYRotation, 0f);
     }
 
     void Morph () {
         if (morphed)
             morphed = false;
         else
             morphed = true;
     }
 }

And the script to change state:

 using UnityEngine;
 using System.Collections;
 
 public class VampireScript : MonoBehaviour {
 
     CharacterController controller;
     public VampireControllerScript controllerScript;
 
     public float coolDown = 15f;
     public float duration = 5f;
     float startCoolDown;
     float startDuration;
 
     public float defaultHeight = 2f;
     public float morphedHeight = 1f;
     public float defaultYposition = 1f;
     public float morphedYposition = 0.5f;
 
     bool morphed;
 
     void Start () {
         controller = GetComponent<CharacterController>();
         startCoolDown = coolDown;
         startDuration = duration;
         coolDown = 0f;
     }
 
     void Update () {
         if (Input.GetButtonDown("Special Ability") && morphed) {
             Morph ();
         }
         if (Input.GetButtonDown("Special Ability") && !morphed) {
             if (coolDown <= 0f) {
                 Morph ();
             }
         }
 
         if (!morphed) {
             controller.height = defaultHeight;
             controller.center = new Vector3 (0f, defaultYposition, 0f);
             //default graphics
             coolDown -= Time.deltaTime;
             duration = startDuration;
         }
         else {
             controller.height = morphedHeight;
             controller.center = new Vector3 (0f, morphedYposition, 0f);
             //morphed graphics
             coolDown = startCoolDown;
             duration -= Time.deltaTime;
             if (duration <= 0f) {
                 Morph();
             }
         }
     }
 
     void Morph () {
         if (!morphed)
             morphed  = true;
         else
             morphed = false;
 
         controllerScript.SendMessage("Morph", SendMessageOptions.RequireReceiver);
     }
 }

So, do you know what could be freezing unity? Thanks in advance.