سلام سه کلاس من به شکل های زیر تعریف شده است

   public class State
    {
        public virtual int StateId { get; set; }
        public virtual string StateName { get; set; }
        public virtual List<City> Cities { get; set; }


    }

    public class City
    {
        public virtual int CityId { get; set; }
        public virtual string CityName { get; set; }
        public virtual State State { get; set; }
        public virtual int StateId { get; set; }
        public virtual List<TownShip> TownShips { get; set; }

    }

   public class TownShip
    {
        public virtual int TownShipId { get; set; }
        public virtual string TownShipName { get; set; }
        public virtual City City { get; set; }
        public virtual int CityId { get; set; }

        public virtual List<Store> Stores { get; set; }
        public virtual List<Person> People { get; set; }
    }

زمانی که در wcf لیستی از کلاس TownShip را فراخوانی میکنم با این ارور مواجه میشم .

An error occurred while receiving the HTTP response to http://localhost:3032/Service1.svc. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.

Server stack trace: 
   at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
   at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
   at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at IService1.GetStates()
   at Service1Client.GetStates()

Inner Exception:
The underlying connection was closed: An unexpected error occurred on a receive.
   at System.Net.HttpWebRequest.GetResponse()
   at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)

Inner Exception:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)

Inner Exception:
An existing connection was forcibly closed by the remote host
   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

اما زمانی که اطتباطات بین کلاس ها را حذف میکنم خطایی رخ نمیدهد ، مهم برای من کلاس های مرتبط به هم هستند که استفاده کنم

لطفا در این خصوص مرا راهنمایی فرمایید.