title: C# Invalid URI: The URI is empty
body: <p>Hello i'm trying to collect all data from website.</p>
  
  <p>On start i collecting all links on that website. After that accessing them.
  The problem is when i accessing multiple pages of website the "Invalid URI: The URI is empty" error is showing in some pages. These are some of those failed urls.</p>
  
  <pre><code>http://syayoyu.com/category/zensinyokudiet
  http://syayoyu.com/fruitgranola-6759.html
  http://syayoyu.com/category/diet/fruitgranola
  </code></pre>
  
  <p>Accessing from browser and accessing them one by one is working ok. But when i try to access in loop the error is occuring. Would you please tell me what is wrong with it.</p>
  
  <p>This is my accessing code</p>
  
  <pre><code>HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
  request.UserAgent = "A .NET Web Crawler";
  WebResponse response = request.GetResponse();
  Stream stream = response.GetResponseStream();
  StreamReader reader = new StreamReader(stream);
  string htmlText = reader.ReadToEnd();
  </code></pre>