Unity Network if use GameObject.Instantiate() the program will disconnect

i use Network.InitializeServer() and Network.Connect() to connect Server and Client. at first it work very well.But when i run GameObject.Instantiate(Resources.Load()) ,Unity throw a error massage like:"The connection request to 192.168.1.3:3000 failed. Are you sure the server can be connected to?".I just want to Instantiate something in local,i dont want to use Network.Instantiate(),(I dont know Network.Instantiate work well or not if i use) can you tell me why?