Cmd is called on Server ERROR!?!!

Everything works if you are the host, but id you are a client, you get this error for every item it tries to spawn. The ItemSpawner class is Located on Empty Objects, Just containing the NetworkIdentity, NetworkTransform, and the class. Here are the classes:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine.Networking;
 
 public class ItemSpawner : NetworkBehaviour{
 
     public List<Item> items = new List<Item>();
 
     public virtual void Init (){
         Debug.Log ("Didn't Initialize Spawner!");
     }
 
     public void addItem(Item item){
 
         items.Add (item);
 
     }
 
     int idOfSpawnedItem;
 
     void Start(){
 
         Init ();
 
         Item spawnedItem;
 
         spawnedItem = items [Random.Range (0, items.Count)];
 
         CmdSpawnItem (spawnedItem.id);
 
     }
 
     [Command]
     public void CmdSpawnItem(int itemId){
 
 
 
         GameObject spawning = (GameObject)Instantiate (ItemHandler.getItemById(itemId).prefab, transform.position, Quaternion.identity);
 
         UnityEngine.Networking.NetworkServer.Spawn (spawning);
 
     }
 
 }


 using UnityEngine;
 using System.Collections;
 
 public class MilitarySpawner : ItemSpawner {
 
     public override void Init(){
 
         addItem (ItemHandler.uzi);
         addItem (ItemHandler.fireaxe);
         addItem (ItemHandler.ump45);
 
     }
 
 }