NullReferenceException: Object reference not set to an instance of an object

Good afternoon friends, I'm suffering from some problems. my code was working perfectly until unity as ben crash gives some errors, can anyone help me?

follow the errors and the code

NullReferenceException: Object reference not set to an instance of an object
PlayerBehaviour.Start () (at Assets/scripts/PlayerBehaviour.cs:52)

NullReferenceException: Object reference not set to an instance of an object
PlayerBehaviour.Update () (at Assets/scripts/PlayerBehaviour.cs:87)

NullReferenceException: Object reference not set to an instance of an object
PlayerBehaviour.Update () (at Assets/scripts/PlayerBehaviour.cs:75)

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public enum TypeCharacter
5. {
6.     Warrior = 0,
7.     Wizard = 1,
8.     Archer = 2
9. }
10.  
11. public enum PlayerStates
12. {
13.     Movement,
14.     Attack,
15. }
16.  
17. public class PlayerBehaviour : CharacterBase
18. {
19.  
20.     private TypeCharacter type;
21.  
22.     private AnimationController animationController;
23.  
24.     //StateMachine
25.     private PlayerStates currentState = PlayerStates.Movement;
26.     //
27.  
28.     //Movimentation
29.     private float speed = 3.0F;
30.     private float speedSideWalk = 3.0F;
31.     public float speedRun;
32.     public float speedWalk;
33.     public float rotateSpeed = 3.0F;
34.     public CharacterController controller;
35.     public Transform focusCamera;
36.     //
37.  
38.     //Attack
39.     private int currentAttack = 0;
40.     public float attackRate;
41.     public int totalAttackAnimations;
42.     private float currentAttackRate;
43.     //
44.  
45.     new protected void Start()
46.     {
47.        
48.         PlayerStatsController.SetTypeCharacter(TypeCharacter.Wizard);
49.         currentLevel = PlayerStatsController.GetCurrentLevel();
50.         type = PlayerStatsController.GetTypeCharacter();
51.  
52.         basicStats = PlayerStatsController.intance.GetBasicStats(type);
53.  
54.         animationController = GetComponent<AnimationController>();
55.         speed = speedWalk;
56.  
57.         controller = GetComponent<CharacterController>();
58.  
59.         base.Start();
60.     }
61.  
62.         // Update is called once per frame
63.         new void Update()
64.     {
65.         base.Update();
66.  
67.         switch (currentState)
68.         {
69.             case PlayerStates.Movement:
70.                 {
71.  
72.                     if (Input.GetKey(KeyCode.LeftShift) || Input.GetAxis("Vertical") != 0)
73.                     {
74.                         speed = speedRun;
75.                         animationController.PlayAnimation(AnimationStates.RUN);
76.                     }
77.                     else
78.                     {
79.                         speed = speedWalk;
80.                         if (Input.GetAxis("Vertical") != 0)
81.                             animationController.PlayAnimation(AnimationStates.WALK);
82.                         else if (Input.GetAxis("Horizontal") != 0)
83.                         {
84.                             animationController.PlayAnimation(AnimationStates.SIDE_WALK);
85.                         }
86.                         else
87.                             animationController.PlayAnimation(AnimationStates.IDDLE);
88.                     }
89.  
90.  
91.                     if (Mathf.Abs(Input.GetAxis("Vertical")) > 0)
92.                     {
93.  
94.                         transform.LookAt(new Vector3(focusCamera.position.x, transform.position.y, focusCamera.position.z));
95.                         Vector3 direction = transform.TransformDirection(Vector3.forward);
96.                         float curSpeed = speed * Input.GetAxis("Vertical");
97.                         controller.SimpleMove(direction * curSpeed);
98.                     }
99.  
100.                     if (Mathf.Abs(Input.GetAxis("Horizontal")) > 0)
101.                     {
102.                         transform.LookAt(new Vector3(focusCamera.position.x, transform.position.y, focusCamera.position.z));
103.                         Vector3 direction = transform.TransformDirection(Vector3.right);
104.                         float curSpeed = speedSideWalk * Input.GetAxis("Horizontal");
105.                         controller.SimpleMove(direction * curSpeed);
106.  
107.                     }
108.  
109.                     //Attack Change State
110.                     if (Input.GetKey(KeyCode.LeftControl))
111.                     {
112.                         currentState = PlayerStates.Attack;
113.                     }
114.  
115.                 }
116.                 break;
117.             case PlayerStates.Attack:
118.                 {
119.                     currentAttackRate += Time.deltaTime;
120.  
121.                     if (currentAttackRate > attackRate)
122.                     {
123.                         currentAttackRate = 0;
124.                         animationController.CallAttackAnimation(currentAttack);
125.                         currentAttack++;
126.  
127.                         if (currentAttack > totalAttackAnimations)
128.                         {
129.                             currentAttack = 0;
130.                         }
131.                     }
132.  
133.                     if (!Input.GetKey(KeyCode.LeftControl))
134.                     {
135.                         currentState = PlayerStates.Movement;
136.                         currentAttackRate = 0;
137.                     }
138.  
139.                 }
140.                 break;
141.  
142.         }
143.  
144.     }
145. }
146.  

 

Have a look at this: https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/