Session not Started in C# when using Bloomberg API

Question

I am working on Bloomberg API, I followed this tutorial

http://holowczak.com/bloomberg-api-csharp-rr/11/

but i am getting error

InvalidOperationException was unhandled : Session not started at line result = session.OpenService("//blp/refdata");

i am new to Bloomberg and want to use its API so please let me know how to rectify these error. Below is my code. Thanks

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Bloomberglp.Blpapi;

namespace Bloomberg
{
    class Program
    {
        static void Main(string[] args)
        {
            bool result;
            bool done = false;
            SessionOptions sessionOptions = new SessionOptions();
            sessionOptions.ServerHost = "localhost";
            sessionOptions.ServerPort = 8194;
            Session session = new Session(sessionOptions);
            result = session.Start();
            result = session.OpenService("//blp/refdata");
            Service referenceService = session.GetService("//blp/refdata");
            Request request = referenceService.CreateRequest("HistoricalDataRequest");
            request.Append("securities", "IBM US Equity");
            request.Append("fields", "PX_LAST");
            request.Set("startDate", "20130601");
            request.Set("endDate", "20130630");
            request.Set("maxDataPoints", 20);
            session.SendRequest(request, null);
            done = false;
            while (!done)
            {
                Event eventObject = session.NextEvent();
                if (eventObject.Type == Event.EventType.RESPONSE)
                {
                    foreach (Message msg in eventObject)
                    {
                        System.Console.WriteLine(msg);
                    }
                    done = true;
                } 
            } 

            Console.ReadKey();

            session.Stop();
        }
    } 
} 

Answer 1

I have run your code on my machine and it works, the print statements print the historical prices of IBM. I was logged into my Bloomberg Terminal when running the code, were you? The info you're requesting is provided by Bloomberg only to Terminal clients, the Terminal license costs about $20K/year but provides a wealth of financial information.