Unity Multiplayer IsLocalPlayer (mirror) return NullPointerException

Hi everyone!
In my game, a multiplayer FPS, all the players move at once if only one press a key.
I tryed to test for

Code (CSharp):

1. GetComponent<NetworkIdentity>().isLocalPlayer

, but it doesnt not work, and it return the following error:

Code (CSharp):

1. NullReferenceException: Object reference not set to an instance of an object
2. PlayerMovement.FixedUpdate () (at Assets/FPS_Movement_Rigidbody-master/PlayerMovement.cs:76)

Here is my full code:

Code (CSharp):

1. // Some stupid rigidbody based movement by Dani
2. //Updated to shoot, and be 'a little bit' multiplayer
3. using System;
4. using UnityEngine;
5. using UnityEngine.UI;
6. using UnityEngine.Networking;
7. public class PlayerMovement : MonoBehaviour {
8.  
9.     //Assingables
10.     public Transform playerCam;
11.     public Transform orientation;
12.    
13.     //Other
14.     private Rigidbody rb;
15.  
16.     //Rotation and look
17.     private float xRotation;
18.     private float sensitivity = 50f;
19.     private float sensMultiplier = 1f;
20.    
21.     //Movement
22.     public float moveSpeed = 4500;
23.     public float maxSpeed = 20;
24.     public bool grounded;
25.     public LayerMask whatIsGround;
26.    
27.     public float counterMovement = 0.175f;
28.     private float threshold = 0.01f;
29.     public float maxSlopeAngle = 35f;
30.  
31.     //Crouch & Slide
32.     private Vector3 crouchScale = new Vector3(1, 0.5f, 1);
33.     private Vector3 playerScale;
34.     public float slideForce = 400;
35.     public float slideCounterMovement = 0.2f;
36.  
37.     //Jumping
38.     private bool readyToJump = true;
39.     private float jumpCooldown = 0.25f;
40.     public float jumpForce = 550f;
41.    
42.     //Shooting (SC)
43.     public GameObject bullet;
44.  
45.     //Life (SC)
46.     public float life=100;
47.     public Text lifetext;
48.     private GameObject spawne;
49.     public GameObject dede;
50.     public GameObject selfi;
51.     //Input
52.     float x, y;
53.     bool jumping, sprinting, crouching;
54.    
55.     //Sliding
56.     private Vector3 normalVector = Vector3.up;
57.     private Vector3 wallNormalVector;
58.  
59.     void Awake() {
60.         rb = GetComponent<Rigidbody>();
61.         lifetext=GameObject.Find("LIFE").GetComponent<Text>();
62.         spawne=GameObject.Find("Spawns");
63.     }
64.    
65.     void Start() {
66.         playerScale =  transform.localScale;
67.         Cursor.lockState = CursorLockMode.Locked;
68.         Cursor.visible = false;
69.     }
70.  
71.    
72.     private void FixedUpdate() {
73.         //if(GetComponent<NetworkIdentity>().isMine)
74. //{
75.         //Debug.Log(GetComponent<NetworkIdentity>().isLocalPlayer());
76.         if(GetComponent<NetworkIdentity>().isLocalPlayer)//GetComponent<NetworkIdentity>().isLocalPlayer)
77.             Movement();
78.     //}
79.     }
80.     private Vector3 getRespawn(){
81.         int children = transform.childCount;//Hi!
82.         Transform[] cows=new Transform[children];
83.          for (int i = 0; i < children; ++i){
84.              cows[i]=transform.GetChild(i);
85.          }
86.    
87.      Vector3 meow=cows[UnityEngine.Random.Range(0, cows.Length)].position;
88.      return meow;
89.     }
90.     private void ded(){
91.         GameObject cow=Instantiate(dede, transform.position, transform.rotation);
92.         //GameObject gerbil=Instantiate(selfi, transform.position, transform.rotation);//Respawn
93.         //Destroy(gameObject);
94.         Destroy(cow, 10f);
95.         Debug.Log("DEED");
96.         life=100;
97.         GameObject[] spawnPoints = GameObject.FindGameObjectsWithTag("spawn");
98.         GameObject currentPoint;
99.         int index=0;
100.          index = UnityEngine.Random.Range (0, spawnPoints.Length);
101.          currentPoint = spawnPoints[index];
102.         transform.position=currentPoint.transform.position;//boo
103.     }
104.     private void Update() {
105.         //if(GetComponent<NetworkIdentity>().isMine){
106.         if(GetComponent<NetworkIdentity>().isLocalPlayer){//GetComponent<NetworkIdentity>().isLocalPlayer){
107.         MyInput();
108.         Look();
109.         lifetext.text="Life: "+life;
110.         if (life<0f) {
111.             ded();
112.         }
113.     }
114.    // }
115.  
116.     }
117.  
118.     /// <summary>
119.     /// Find user input. Should put this in its own class but im lazy
120.     /// </summary>
121.    
122.     private void MyInput() {
123.         x = Input.GetAxisRaw("Horizontal");
124.         y = Input.GetAxisRaw("Vertical");
125.         jumping = Input.GetButton("Jump");
126.         crouching = Input.GetKey(KeyCode.LeftControl);
127.         //Shooting(SC)
128.      
129.  
130.      
131.         //Crouching
132.         if (Input.GetKeyDown(KeyCode.LeftControl))
133.             StartCrouch();
134.         if (Input.GetKeyUp(KeyCode.LeftControl))
135.             StopCrouch();
136.     }
137.  
138.     private void StartCrouch() {
139.         transform.localScale = crouchScale;
140.         transform.position = new Vector3(transform.position.x, transform.position.y - 0.5f, transform.position.z);
141.         if (rb.velocity.magnitude > 0.5f) {
142.             if (grounded) {
143.                 rb.AddForce(orientation.transform.forward * slideForce);
144.             }
145.         }
146.     }
147.  
148.     private void StopCrouch() {
149.         transform.localScale = playerScale;
150.         transform.position = new Vector3(transform.position.x, transform.position.y + 0.5f, transform.position.z);
151.     }
152.  
153.     private void Movement() {
154.         //Extra gravity
155.         rb.AddForce(Vector3.down * Time.deltaTime * 10);
156.        
157.         //Find actual velocity relative to where player is looking
158.         Vector2 mag = FindVelRelativeToLook();
159.         float xMag = mag.x, yMag = mag.y;
160.  
161.         //Counteract sliding and sloppy movement
162.         CounterMovement(x, y, mag);
163.        
164.         //If holding jump && ready to jump, then jump
165.         if (readyToJump && jumping) Jump();
166.  
167.         //Set max speed
168.         float maxSpeed = this.maxSpeed;
169.        
170.         //If sliding down a ramp, add force down so player stays grounded and also builds speed
171.         if (crouching && grounded && readyToJump) {
172.             rb.AddForce(Vector3.down * Time.deltaTime * 3000);
173.             return;
174.         }
175.        
176.         //If speed is larger than maxspeed, cancel out the input so you don't go over max speed
177.         if (x > 0 && xMag > maxSpeed) x = 0;
178.         if (x < 0 && xMag < -maxSpeed) x = 0;
179.         if (y > 0 && yMag > maxSpeed) y = 0;
180.         if (y < 0 && yMag < -maxSpeed) y = 0;
181.  
182.         //Some multipliers
183.         float multiplier = 1f, multiplierV = 1f;
184.        
185.         // Movement in air
186.         if (!grounded) {
187.             multiplier = 0.5f;
188.             multiplierV = 0.5f;
189.         }
190.        
191.         // Movement while sliding
192.         if (grounded && crouching) multiplierV = 0f;
193.  
194.         //Apply forces to move player
195.         rb.AddForce(orientation.transform.forward * y * moveSpeed * Time.deltaTime * multiplier * multiplierV);
196.         rb.AddForce(orientation.transform.right * x * moveSpeed * Time.deltaTime * multiplier);
197.     }
198.  
199.     private void Jump() {
200.         if (grounded && readyToJump) {
201.             readyToJump = false;
202.  
203.             //Add jump forces
204.             rb.AddForce(Vector2.up * jumpForce * 1.5f);
205.             rb.AddForce(normalVector * jumpForce * 0.5f);
206.            
207.             //If jumping while falling, reset y velocity.
208.             Vector3 vel = rb.velocity;
209.             if (rb.velocity.y < 0.5f)
210.                 rb.velocity = new Vector3(vel.x, 0, vel.z);
211.             else if (rb.velocity.y > 0)
212.                 rb.velocity = new Vector3(vel.x, vel.y / 2, vel.z);
213.            
214.             Invoke(nameof(ResetJump), jumpCooldown);
215.         }
216.     }
217.    
218.     private void ResetJump() {
219.         readyToJump = true;
220.     }
221.    
222.     private float desiredX;
223.     private void Look() {
224.         float mouseX = Input.GetAxis("Mouse X") * sensitivity * Time.fixedDeltaTime * sensMultiplier;
225.         float mouseY = Input.GetAxis("Mouse Y") * sensitivity * Time.fixedDeltaTime * sensMultiplier;
226.  
227.         //Find current look rotation
228.         Vector3 rot = playerCam.transform.localRotation.eulerAngles;
229.         desiredX = rot.y + mouseX;
230.        
231.         //Rotate, and also make sure we dont over- or under-rotate.
232.         xRotation -= mouseY;
233.         xRotation = Mathf.Clamp(xRotation, -90f, 90f);
234.  
235.         //Perform the rotations
236.         playerCam.transform.localRotation = Quaternion.Euler(xRotation, desiredX, 0);
237.         orientation.transform.localRotation = Quaternion.Euler(0, desiredX, 0);
238.     }
239.  
240.     private void CounterMovement(float x, float y, Vector2 mag) {
241.         if (!grounded || jumping) return;
242.  
243.         //Slow down sliding
244.         if (crouching) {
245.             rb.AddForce(moveSpeed * Time.deltaTime * -rb.velocity.normalized * slideCounterMovement);
246.             return;
247.         }
248.  
249.         //Counter movement
250.         if (Math.Abs(mag.x) > threshold && Math.Abs(x) < 0.05f || (mag.x < -threshold && x > 0) || (mag.x > threshold && x < 0)) {
251.             rb.AddForce(moveSpeed * orientation.transform.right * Time.deltaTime * -mag.x * counterMovement);
252.         }
253.         if (Math.Abs(mag.y) > threshold && Math.Abs(y) < 0.05f || (mag.y < -threshold && y > 0) || (mag.y > threshold && y < 0)) {
254.             rb.AddForce(moveSpeed * orientation.transform.forward * Time.deltaTime * -mag.y * counterMovement);
255.         }
256.        
257.         //Limit diagonal running. This will also cause a full stop if sliding fast and un-crouching, so not optimal.
258.         if (Mathf.Sqrt((Mathf.Pow(rb.velocity.x, 2) + Mathf.Pow(rb.velocity.z, 2))) > maxSpeed) {
259.             float fallspeed = rb.velocity.y;
260.             Vector3 n = rb.velocity.normalized * maxSpeed;
261.             rb.velocity = new Vector3(n.x, fallspeed, n.z);
262.         }
263.     }
264.  
265.     /// <summary>
266.     /// Find the velocity relative to where the player is looking
267.     /// Useful for vectors calculations regarding movement and limiting movement
268.     /// </summary>
269.     /// <returns></returns>
270.     public Vector2 FindVelRelativeToLook() {
271.         float lookAngle = orientation.transform.eulerAngles.y;
272.         float moveAngle = Mathf.Atan2(rb.velocity.x, rb.velocity.z) * Mathf.Rad2Deg;
273.  
274.         float u = Mathf.DeltaAngle(lookAngle, moveAngle);
275.         float v = 90 - u;
276.  
277.         float magnitue = rb.velocity.magnitude;
278.         float yMag = magnitue * Mathf.Cos(u * Mathf.Deg2Rad);
279.         float xMag = magnitue * Mathf.Cos(v * Mathf.Deg2Rad);
280.        
281.         return new Vector2(xMag, yMag);
282.     }
283.  
284.     private bool IsFloor(Vector3 v) {
285.         float angle = Vector3.Angle(Vector3.up, v);
286.         return angle < maxSlopeAngle;
287.     }
288.  
289.     private bool cancellingGrounded;
290.    
291.     /// <summary>
292.     /// Handle ground detection
293.     /// </summary>
294.     private void OnCollisionStay(Collision other) {
295.         //Make sure we are only checking for walkable layers
296.         int layer = other.gameObject.layer;
297.         if (whatIsGround != (whatIsGround | (1 << layer))) return;
298.  
299.         //Iterate through every collision in a physics update
300.         for (int i = 0; i < other.contactCount; i++) {
301.             Vector3 normal = other.contacts[i].normal;
302.             //FLOOR
303.             if (IsFloor(normal)) {
304.                 grounded = true;
305.                 cancellingGrounded = false;
306.                 normalVector = normal;
307.                 CancelInvoke(nameof(StopGrounded));
308.             }
309.         }
310.  
311.         //Invoke ground/wall cancel, since we can't check normals with CollisionExit
312.         float delay = 3f;
313.         if (!cancellingGrounded) {
314.             cancellingGrounded = true;
315.             Invoke(nameof(StopGrounded), Time.deltaTime * delay);
316.         }
317.     }
318.  
319.     private void StopGrounded() {
320.         grounded = false;
321.     }
322.    
323. }
324.  

Have a good day(and please, help me).

 

Check out our documentation and examples.
NetworkMovement needs to be of type NetworkBehaviour and you need a NetworkIdentity component too

 

I added a NetworkIdentity, checked it twice (or more?)
Also, i checked examples, and they use isLocalPlayer, and it work fine...
Here is a screenshot of my NetworkIdentity on player (Player_Used):

 

The img src is : https://ibb.co/V9bjMT6

 

Check that your GetComponent<NetworkIdentity>() call is actually returning an instance of NetworkIdentity instead of null before you try to use it.