title: HttpWebRequest: The request was aborted: Could not create SSL/TLS secure channel
body: <p>I'm making a asp.net web forms application which offers to pay using paypal. The application is supposed to make use of ssl. When i run my application all goes well until i select my button pay by paypal. When i press this button the following error occurs:</p>
  
  <blockquote>
    <p>The request was aborted: Could not create SSL/TLS secure channel.</p>
    
    <p>Description: An unhandled exception occurred during the execution of
    the current web request. Please review the stack trace for more
    information about the error and where it originated in the code. </p>
    
    <p>Exception Details: System.Net.WebException: The request was aborted:
    Could not create SSL/TLS secure channel.</p>
    
    <p>Source Error: </p>
    
    <p>Line 203: Line 204:        //Retrieve the Response returned from the
    NVP API call to PayPal. Line 205:        HttpWebResponse objResponse =
    (HttpWebResponse)objRequest.GetResponse(); Line 206:        string
    result; Line 207:        using (StreamReader sr = new
    StreamReader(objResponse.GetResponseStream()))</p>
    
    <p>Source File: C:\Users\willem\documents\visual studio
    2015\Projects\WingtipToys\WingtipToys\Logic\PayPalFunctions.cs<br>
    Line: 205</p>
  </blockquote>
  
  <p>Below my method in which the error ocurs</p>
  
  <pre><code>public string HttpCall(string NvpRequest)
  {
      string url = pEndPointURL;
  
      string strPost = NvpRequest + "&amp;" + buildCredentialsNVPString();
      strPost = strPost + "&amp;BUTTONSOURCE=" + HttpUtility.UrlEncode(BNCode);
  
      HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
      objRequest.Timeout = Timeout;
      objRequest.Method = "POST";
      //objRequest.ContentLength = strPost.Length;
  
      try
      {
          using (StreamWriter myWriter = new StreamWriter(objRequest.GetRequestStream()))
          {
              myWriter.Write(strPost);
          }
      }
      catch (Exception)
      {
          // No logging for this tutorial.
      }
  
      //Retrieve the Response returned from the NVP API call to PayPal.
      HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
      string result;
      using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
      {
          result = sr.ReadToEnd();
      }
  
      return result;
  }
  </code></pre>