Help with Unet

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Networking;

public class Client : NetworkBehaviour {
    public GameObject PlayerObject;
    public GameObject PlayerObjectPrefab;
    public NetworkIdentity NI;

    void Start ()
    {
        if (!isLocalPlayer) return;
        NI = GetComponent<NetworkIdentity>();
    }
    void Update () {
        if (!isLocalPlayer) return;
        if (Input.GetKeyDown(KeyCode.I))
        {
            SpawnPlayerObject();
        }
        if (PlayerObject != null)
        {
            if (Input.GetKeyDown(KeyCode.W))
            {
                PlayerObject.transform.Translate(Vector3.forward * 3f);
            }
            if (Input.GetKeyDown(KeyCode.S))
            {
                PlayerObject.transform.Translate(Vector3.back * 3f);
            }
            if (Input.GetKeyDown(KeyCode.A))
            {
                PlayerObject.transform.Translate(Vector3.left * 3f);
            }
            if (Input.GetKeyDown(KeyCode.D))
            {
                PlayerObject.transform.Translate(Vector3.right * 3f);
            }
        }
    }
    void SpawnPlayerObject()
    {
        if (PlayerObject != null) NetworkServer.Destroy(PlayerObject);
        if (isServer)
        {
            PlayerObject = Instantiate(PlayerObjectPrefab);
            NetworkIdentity ObjectIdentity = PlayerObject.GetComponent<NetworkIdentity>();
            ObjectIdentity.localPlayerAuthority = true;
            RpcSpawnPlayerObject(NI);
        }
        else
        {
            PlayerObject = Instantiate(PlayerObjectPrefab);
            NetworkIdentity ObjectIdentity = PlayerObject.GetComponent<NetworkIdentity>();
            ObjectIdentity.localPlayerAuthority = true;
            CmdSpawnPlayerObject( NI);
        }
    }
    [Command]
    void CmdSpawnPlayerObject( NetworkIdentity _PlayerIdentity)
    {
        GameObject Pgo = NetworkServer.FindLocalObject(_PlayerIdentity.netId);
        GameObject newplayerobject = Instantiate(PlayerObjectPrefab);
        Pgo.GetComponent<Client>().PlayerObject = newplayerobject;
        RpcSpawnPlayerObject(_PlayerIdentity);
    }

    [ClientRpc]
    void RpcSpawnPlayerObject( NetworkIdentity _PlayerIdentity)
    {
        GameObject Pgo = NetworkServer.FindLocalObject(_PlayerIdentity.netId);
        if (NI != _PlayerIdentity)
        {
            GameObject newplayerobject = Instantiate(PlayerObjectPrefab);
            Pgo.GetComponent<Client>().PlayerObject = newplayerobject;
        }

    }
}