View ID AllocatedID: X not found during lookup.

After two calls RPC, when run script CreepDie (), appear 2 errors .

1) View ID AllocatedID: 3 not found during lookup. Strange behaviour may occur

2) Could't invoke RPC function 'SetDamage' because the networkView 'AllocatedID: 3' doesn't exist

 void OnCollisionEnter (Collision collision)
 {                        
     if(collision.collider.gameObject.tag == "AI")
     {
             
         NetworkView NetworkViewCreep = collision.collider.gameObject.networkView;    
         
         NetworkView nView;
         nView = collision.collider.gameObject.GetComponent<NetworkView>();
         Debug.Log("Collide GameObject "+nView.viewID);            
             
         if(Network.isServer)
         NetworkViewCreep.RPC("SetDamage",RPCMode.All,10);
                     
     }
 }
 
 
 
 [RPC]    
 public void SetDamage(int Damage)
 {
     Debug.Log("Set Damage "+ Damage);
     
     if(Damage<20)
     {
         HP -= Damage;
         Debug.Log("Hp "+HP);
     }
     else
     {
         Debug.Log("Creep Die");            
         CreepDie();    
     }
 }    
 
 
 [RPC]
 public void CreepDie()
 {
     if(this.gameObject.transform.parent.gameObject!=null && Network.isServer)
     {
         Network.RemoveRPCs(this.gameObject.transform.parent.gameObject.networkView.viewID); 
         Network.Destroy(this.gameObject.transform.parent.gameObject);
     }
 }