I use a network platform to validate my users to allow use application but i have some error pleas if possible help me thank you for help and my error is:

> 
> 2013-07-04 15:06:14 - NPMessage: DEBUG: Dispatching a
>  RPCAuthenticateValidateTicketMessage 2013-07-04 15:06:14 - NPMessage:
>  ERROR: System.ArgumentOutOfRangeException: Index was out of range.
>  Must be non-negative and less than the size of the collection.
>  Parameter name: startIndex
>  at System.BitConverter.ToUInt64(Byte[] value, Int32 startIndex)
>  at NPx.RPCAuthenticateValidateTicketMessage.ReadTicket(Byte[] bytes)
>  at NPx.RPCAuthenticateValidateTicketMessage.Process(NPHandler client)
>  at NPx.NPMessage.Process()
> 
> 
> 

and my source is:

```
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;

using NPx;

namespace NPx
{
 public partial class RPCAuthenticateValidateTicketMessage : NPRPCMessage<AuthenticateValidateTicketMessage>
 {
     public override void Process(NPHandler client)
     {
         var ipNum = (uint)IPAddress.NetworkToHostOrder(Message.clientIP);
         var ip = new IPAddress(BitConverter.GetBytes(ipNum));
         var ticket = ReadTicket(Message.ticket);
         var npid = Message.npid;

         if (npid == 0)
         {
             npid = ticket.clientID;
         }

         var valid = false;
         var groupID = 0;

         if (ticket.version == 1)
         {
             if (client.NPID == (long)ticket.serverID)
             {
                 if (npid == ticket.clientID)
                 {
                     var remoteClient = NPSocket.GetClient((long)ticket.clientID);
                     remoteClient.CurrentServer = client.NPID;

                     if (remoteClient != null && !remoteClient.Unclean)
                     {
                         Log.Debug("Ticket auth: remote address " + remoteClient.Address.Address.ToString());
                         Log.Debug("Ticket auth: message address " + ip.ToString());

                         if (ipNum == 0 || remoteClient.Address.Address.Equals(ip))
                         {
                             valid = true;

                             groupID = remoteClient.GroupID;

                             Log.Debug("Successfully authenticated a ticket for client " + remoteClient.NPID.ToString("x16"));
                         }
                         else
                         {
                             Log.Debug("Ticket auth: IP address didn't match.");
                         }
                     }
                     else
                     {
                         Log.Debug("Ticket auth: no such client");
                     }
                 }
                 else
                 {
                     Log.Debug("Ticket auth: NPID didn't match.");
                 }
             }
             else
             {
                 Log.Debug("Ticket auth: server NPID didn't match.");
             }
         }
         else
         {
             Log.Debug("Ticket auth: version didn't match.");
         }

         var reply = MakeResponse<AuthenticateValidateTicketResultMessage>(client);
         reply.Message.result = (valid) ? 0 : 1;
         reply.Message.groupID = groupID;
         reply.Message.npid = npid;
         reply.Send();
     }

     private class NPTicket
     {
         public int version;
         public ulong clientID;
         public ulong serverID;
         public uint time;
     }

     private NPTicket ReadTicket(byte[] bytes)
     {
         var ticket = new NPTicket();
         ticket.version = BitConverter.ToInt32(bytes, 0);

         if (ticket.version == 1)
         {
             ticket.clientID = BitConverter.ToUInt64(bytes, 4);
             ticket.serverID = BitConverter.ToUInt64(bytes, 12);
             ticket.time = BitConverter.ToUInt32(bytes, 20);
         }

         return ticket;
     }
 }
....   
}

```