如何修复“试图在没有权限的情况下为对象发送命令”？

Question

我确实有一个Android多人游戏。我有一个脚本，玩家可以在其中发射武器。但是我确实收到了此错误“尝试在未经授权的情况下为对象发送命令。

我看到了以下答案：https://stackoverflow.com/a/42689614，但是我不知道如何在我的代码中实现它。

这是我当前的播放器脚本代码。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Networking;
namespace S3 { 
[RequireComponent(typeof(CharacterController))]
public class MPPlayerController : NetworkBehaviour {

//Handling
public float rotationSpeed = 450;
public float walksSpeed = 5;
public float runSpeed = 8;
    public AudioClip shootAudio;
    //System
    private Quaternion targetRotation;
//Components  
private CharacterController controller;

public GameObject bulletPrefab;
public Transform bulletSpawn;

void Start()
{

    controller = GetComponent<CharacterController>();

}


void Update()
{
    if (!isLocalPlayer) 
    {
        return;
    }
    Vector3 input = new Vector3(Input.GetAxisRaw("Horizontal"), 0, Input.GetAxisRaw("Vertical"));

    if (input != Vector3.zero)
    {
        targetRotation = Quaternion.LookRotation(input);
        transform.eulerAngles = Vector3.up * Mathf.MoveTowardsAngle(transform.eulerAngles.y, targetRotation.eulerAngles.y, rotationSpeed * Time.deltaTime);
    }
    Vector3 motion = input;
    motion *= (Mathf.Abs(input.x) == 1 && Mathf.Abs(input.z) == 1) ? 0.7f : 1;
    motion *= (Input.GetButton("Run")) ? runSpeed : walksSpeed;
    motion += Vector3.up * -8;

    controller.Move(motion * Time.deltaTime);

    if (Input.GetKeyDown(KeyCode.Space))
    {
                CmdFire ();
    }
}


[Command]
    void CmdFire()
{

        //create the bullet from the prefab
            GameObject bullet = (GameObject)Instantiate (bulletPrefab, bulletSpawn.position, bulletSpawn.rotation);
            AudioManager.instance.PlaySound (shootAudio, transform.position);

            //add velocity to the bullet
            bullet.GetComponent<Rigidbody> ().velocity = bullet.transform.forward * 20.0f;

            //spawn the bullet on the clients
            NetworkServer.Spawn (bullet);

            //destroy the bullet after 2 seconds
            Destroy (bullet, 2);
}
    public override void OnStartLocalPlayer()
    {
        GetComponent<MeshRenderer>().material.color = Color.blue;
    }
}

}