.NET DevDefined IPP Platform Reconnect Call

IPP-Platform-Reconnect.cs

using DevDefined.OAuth.Consumer;
using DevDefined.OAuth.Framework;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Runtime.Serialization.Formatters.Binary;
using System.Net;

namespace IPPQbApiConsoleApp
{
    static class SampleCalls
    {
        public static string ReconnectRealm(string consumerKey, string consumerSecret, string accessToken, string accessTokenSecret)
        {
            HttpWebRequest httpWebRequest = WebRequest.Create("https://appcenter.intuit.com/api/v1/Connection/Reconnect") as HttpWebRequest;
            httpWebRequest.Method = "GET";
            httpWebRequest.Headers.Add("Authorization", GetDevDefinedOAuthHeader(httpWebRequest, consumerKey, consumerSecret, accessToken, accessTokenSecret));
            UTF8Encoding encoding = new UTF8Encoding();
            HttpWebResponse httpWebResponse = httpWebRequest.GetResponse() as HttpWebResponse;
            using (Stream data = httpWebResponse.GetResponseStream())
            {
                //return XML response
                return new StreamReader(data).ReadToEnd();
            }
        }

        static string GetDevDefinedOAuthHeader(HttpWebRequest webRequest, string consumerKey, string consumerSecret, string accessToken, string accessTokenSecret)
        {

            OAuthConsumerContext consumerContext = new OAuthConsumerContext
            {
                ConsumerKey = consumerKey,
                ConsumerSecret = consumerSecret,
                SignatureMethod = SignatureMethod.HmacSha1,
                UseHeaderForOAuthParameters = true

            };

            consumerContext.UseHeaderForOAuthParameters = true;

            //URIs not used - we already have Oauth tokens
            OAuthSession oSession = new OAuthSession(consumerContext, "https://www.example.com",
                                    "https://www.example.com",
                                    "https://www.example.com");


            oSession.AccessToken = new TokenBase
            {
                Token = accessToken,
                ConsumerKey = consumerKey,
                TokenSecret = accessTokenSecret
            };

            IConsumerRequest consumerRequest = oSession.Request();
            consumerRequest = ConsumerRequestExtensions.ForMethod(consumerRequest, webRequest.Method);
            consumerRequest = ConsumerRequestExtensions.ForUri(consumerRequest, webRequest.RequestUri);
            consumerRequest = consumerRequest.SignWithToken();
            return consumerRequest.Context.GenerateOAuthParametersForHeader();
        }

    }
}

#endregion

Why am I getting this response. Please help

   <?xml version="1.0" encoding="utf-8"?>
     <ReconnectResponse xmlns:xsd="http://www.w3.org/2001/XMLSchema"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://platform.intuit.com/api/v1">
   <ErrorMessage>OAuth Token rejected</ErrorMessage>
    <ErrorCode>270</ErrorCode>
   <ServerTime>2015-04-01T10:41:11.5739677Z</ServerTime>
</ReconnectResponse>

@DureSameen:
This error occurs when you are trying to renew an invalid access token. This can happen if someone disconnected from QuickBooks or if it is already expired. You can only quietly renew an access token in the background before it expires but only if it will expired within the next 30 days. If you get this, that means the user needs to reconnect/authorize your app to get a new access token.