title: While uploading tracks to soundcloud(422) Unprocessable Entity)
body: <p>I would like to try upload a mp3 file to my soundcloud account. I have written this code for this job.</p>
  
  <pre><code>                        WebClient client = new WebClient();
                          string postData = "client_id=" + "xxxxx"
                                          + "&amp;client_secret=" + "xxx"
                                          + "&amp;grant_type=password&amp;username=" + "xxx" //your username
                                          + "&amp;password=" + "xxx";//your password :)
                          string soundCloudTokenRes = "https://api.soundcloud.com/oauth2/token";
                          string tokenInfo = client.UploadString(soundCloudTokenRes, postData);
                          tokenInfo = tokenInfo.Remove(0, tokenInfo.IndexOf("token\":\"") + 8);
                          string token = tokenInfo.Remove(tokenInfo.IndexOf("\""));
                          System.Net.ServicePointManager.Expect100Continue = false;
                          var request = WebRequest.Create("https://api.soundcloud.com/tracks") as HttpWebRequest;
                          request.CookieContainer = new CookieContainer();
                          //some default headers
                          request.Accept = "*/*";
                          request.Headers.Add("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.3");
                          request.Headers.Add("Accept-Encoding", "gzip,deflate,sdch");
                          request.Headers.Add("Accept-Language", "en-US,en;q=0.8,ru;q=0.6");
                          //file array
                          var files = new UploadFile[] { new UploadFile(filePath, "@/" + filePath, "application/octet-stream") };
                          //other form data
                          var form = new NameValueCollection();
                          form.Add("track[title]", "biksad");
                          form.Add("track[sharing]", "public");
                          form.Add("oauth_token", token);
                          form.Add("format", "json");
  
                          form.Add("Filename", fileName);
                          form.Add("Upload", "Submit Query");
                          string lblInfo;
                          try
                          {
                              using (var response = HttpUploadHelper.Upload(request, files, form))
                              {
                                  using (var reader = new StreamReader(response.GetResponseStream()))
                                  {
                                      lblInfo = reader.ReadToEnd();
                                  }
                              }
                          }
                          catch (Exception ex)
                          {
                              lblInfo = ex.ToString();
                          }
                      }
  </code></pre>
  
  <p>When I debug this code part. I get (422) Unprocessable Entity error in catch block. Why I get this error? How can solve this problem?  </p>