title: Linq2Twitter Single User Authorisation Null Value Exception
body: <p>I've been developing an internal ASP.NET web forms application for our business and one of the requirements is to display our Twitter feed on our portal home page to all users.</p>
  
  <p>For this I've decided that it is best to use LinqToTwitter Single User Authorisation to get the statuses for everyone without them having to authenticate their own accounts.</p>
  
  <p>My main problem at the minute is that when we use the auth object to get the TwitterContext, it returns with an error on the TwitterContext saying</p>
  
  <pre><code>Value cannot be null
  </code></pre>
  
  <p>on every internal context object.</p>
  
  <p>I've gone through our twitter application settings at <a href="http://dev.twitter.com" rel="nofollow">http://dev.twitter.com</a> and I have our correct consumer key/token and access key/token. The permission for the application is set to Read-Only. There is no callback URL specified on the <a href="http://dev.twitter.com" rel="nofollow">http://dev.twitter.com</a> website as it is currently on our internal system (so it wouldn't be able to get back anyway). Is this where it is going wrong? Do I need to forward some ports and allow the callback to get through to our development machines?</p>
  
  <p>Here's the code for prudence. As far as I can see, there is nothing wrong with it. I know that it is set to <code>.FirstOrDefault</code>, this was just for seeing whether it is actually getting anything (which it isn't).</p>
  
  <p>Thanks for any help you can give! :)</p>
  
  <pre><code>private async Task GetTweets()
  {
      var auth = new SingleUserAuthorizer
      {
          CredentialStore = new SingleUserInMemoryCredentialStore
          {
              ConsumerKey = ConfigurationManager.AppSettings["consumerKey"],
              ConsumerSecret = ConfigurationManager.AppSettings["consumerSecret"],
              AccessToken = ConfigurationManager.AppSettings["accessToken"],
              AccessTokenSecret = ConfigurationManager.AppSettings["accessTokenSecret"],
          }
      };
      try
      {
          using (TwitterContext twitterContext = new TwitterContext(auth))
          {
              var searchResponse = await (from c in twitterContext.Status
                                          where c.Type == StatusType.User
                                          &amp;&amp; c.ScreenName == "my_screenname"
                                          select c).ToListAsync();
              Tb_home_news.Text = searchResponse.FirstOrDefault().Text;
          }
      }
      catch (Exception ex)
      {
          Tb_home_news.Text = ex.Message;
      }
  }
  </code></pre>