title: Error in passing data to the web service. 'NSInvalidArgumentException', reason: 'Invalid (non-string) key in JSON dictionary'
body: <p>I'm trying to pass the twitter feeds that i save on the UserDefaults to the WebService. the WebService works because i'm using it on the passing the feeds from Facebook.</p>
  
  <pre><code>- (void) fetchedTwitterFeeds: (NSString *)screenname{
  STTwitterAPI * twit = [STTwitterAPI twitterAPIAppOnlyWithConsumerKey:twitter_id consumerSecret:twitter_secret];
  
  if ([[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_SCREEN_NAME] !=nil) {
      screenname = [NSString stringWithFormat:@"%@", [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_SCREEN_NAME]];
  }
  
  [twit verifyCredentialsWithSuccessBlock:^(NSString * username){
      [twit getUserTimelineWithScreenName:screenname successBlock:^(NSArray * statuses){
          self.feeds = [NSMutableArray arrayWithArray:statuses];
          NSLog(@"Twitter Feeds Login: %@", feeds);
  
          NSLog(@"Session Token: %@", [[NSUserDefaults standardUserDefaults] valueForKey:SESSION_TOKEN]);
          NSLog(@"Track ID: %d", track_id);
          NSLog(@"Tweets: %@", [feeds valueForKey:@"text"]);
          NSLog(@"Created at: %@", [feeds valueForKey:@"created_at"]);
          NSLog(@"Country: %@", [[feeds valueForKey:@"place"] valueForKey:@"country"]);
          NSLog(@"Place Name: %@", [[feeds valueForKey:@"place"] valueForKey:@"full_name"]);
          NSLog(@"Sample Lat: -75.14310264");
          NSLog(@"Sample Long: 40.05701649");
          NSLog(@"Media URL: %@", [[[feeds valueForKey:@"entities"] valueForKey:@"media"] valueForKey:@"media_url"]);
          NSLog(@"Provider Name: %@", TWITTER_PROVIDER);
  
          //Saving Feeds
          if ([feeds valueForKey:@"text"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:[feeds valueForKey:@"text"] forKey:TWITTER_FEED_TWEETS_KEY];
          else[[NSUserDefaults standardUserDefaults] setObject:@"No Tweets" forKey:TWITTER_FEED_TWEETS_KEY];
  
          if ([feeds valueForKey:@"created_at"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:[feeds valueForKey:@"created_at"] forKey:TWITTER_FEED_DATE_CREATED_KEY];
          else[[NSUserDefaults standardUserDefaults] setObject:@"No Date Created" forKey:TWITTER_FEED_DATE_CREATED_KEY];
  
          if ([feeds valueForKey:@"created_at"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:[[feeds valueForKey:@"place"] valueForKey:@"country"] forKey:TWITTER_FEED_COUNTRY_KEY];
          else[[NSUserDefaults standardUserDefaults] setObject:@"No Country" forKey:TWITTER_FEED_COUNTRY_KEY];
  
          if ([feeds valueForKey:@"created_at"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:[[feeds valueForKey:@"place"] valueForKey:@"full_name"] forKey:TWITTER_FEED_PLACE_NAME_KEY];
          else[[NSUserDefaults standardUserDefaults] setObject:@"No Place Name" forKey:TWITTER_FEED_PLACE_NAME_KEY];
  
          if ([feeds valueForKey:@"created_at"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:@"-75.14310264" forKey:TWITTER_FEED_LATITUDE_KEY];
  
          if ([feeds valueForKey:@"created_at"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:@"40.05701649" forKey:TWITTER_FEED_LONGITUDE_KEY];
  
          if ([feeds valueForKey:@"created_at"] !=nil)[[NSUserDefaults standardUserDefaults] setObject:[[[feeds valueForKey:@"entities"] valueForKey:@"media"] valueForKey:@"media_url"] forKey:TWITTER_FEED_MEDIA_URL_KEY];
          else[[NSUserDefaults standardUserDefaults] setObject:@"No Media " forKey:TWITTER_FEED_MEDIA_URL_KEY];
  
      }errorBlock:^(NSError * error){
          NSLog(@"%@", error.debugDescription);
      }];
  }errorBlock:^(NSError * error){
      NSLog(@"%@", error.debugDescription);
  }];
  }
  </code></pre>
  
  <p>And heres the twitter Feeds i get when i NSLog(@"Twitter Feeds Login: %@", feeds) :</p>
  
  <pre><code>    2014-08-19 15:42:10.497 backtrack[11009:60b] Twitter Feeds Login: (
      {
      contributors = "&lt;null&gt;";
      coordinates = "&lt;null&gt;";
      "created_at" = "Tue Aug 19 04:50:45 +0000 2014";
      entities =         {
          hashtags =             (
          );
          media =             (
                              {
                  "display_url" = "pic.twitter.com/kKBrsjf4GO";
                  "expanded_url" = "http://twitter.com/calsofer/status/501592079156273152/photo/1";
                  id = 501592077608562689;
                  "id_str" = 501592077608562689;
                  indices =                     (
                      5,
                      27
                  );
                  "media_url" = "http://pbs.twimg.com/media/BvYDVkgCMAEBucu.png";
                  "media_url_https" = "https://pbs.twimg.com/media/BvYDVkgCMAEBucu.png";
                  sizes =                     {
                      large =                         {
                          h = 120;
                          resize = fit;
                          w = 120;
                      };
                      medium =                         {
                          h = 120;
                          resize = fit;
                          w = 120;
                      };
                      small =                         {
                          h = 120;
                          resize = fit;
                          w = 120;
                      };
                      thumb =                         {
                          h = 120;
                          resize = crop;
                          w = 120;
                      };
                  };
                  type = photo;
                  url = "http://t.co/kKBrsjf4GO";
              }
          );
          symbols =             (
          );
          urls =             (
          );
          "user_mentions" =             (
          );
      };
      "extended_entities" =         {
          media =             (
                              {
                  "display_url" = "pic.twitter.com/kKBrsjf4GO";
                  "expanded_url" = "http://twitter.com/calsofer/status/501592079156273152/photo/1";
                  id = 501592077608562689;
                  "id_str" = 501592077608562689;
                  indices =                     (
                      5,
                      27
                  );
                  "media_url" = "http://pbs.twimg.com/media/BvYDVkgCMAEBucu.png";
                  "media_url_https" = "https://pbs.twimg.com/media/BvYDVkgCMAEBucu.png";
                  sizes =                     {
                      large =                         {
                          h = 120;
                          resize = fit;
                          w = 120;
                      };
                      medium =                         {
                          h = 120;
                          resize = fit;
                          w = 120;
                      };
                      small =                         {
                          h = 120;
                          resize = fit;
                          w = 120;
                      };
                      thumb =                         {
                          h = 120;
                          resize = crop;
                          w = 120;
                      };
                  };
                  type = photo;
                  url = "http://t.co/kKBrsjf4GO";
              }
          );
      };
      "favorite_count" = 0;
      favorited = 0;
      geo = "&lt;null&gt;";
      id = 501592079156273152;
      "id_str" = 501592079156273152;
      "in_reply_to_screen_name" = "&lt;null&gt;";
      "in_reply_to_status_id" = "&lt;null&gt;";
      "in_reply_to_status_id_str" = "&lt;null&gt;";
      "in_reply_to_user_id" = "&lt;null&gt;";
      "in_reply_to_user_id_str" = "&lt;null&gt;";
      lang = en;
      place =         {
          attributes =             {
          };
          "bounding_box" =             {
              coordinates =                 (
                                      (
                                              (
                          "-8.662663",
                          "49.1626564"
                      ),
                                              (
                          "1.768926",
                          "49.1626564"
                      ),
                                              (
                          "1.768926",
                          "60.86165"
                      ),
                                              (
                          "-8.662663",
                          "60.86165"
                      )
                  )
              );
              type = Polygon;
          };
          "contained_within" =             (
          );
          country = "United Kingdom";
          "country_code" = GB;
          "full_name" = "United Kingdom";
          id = 6416b8512febefc9;
          name = "United Kingdom";
          "place_type" = country;
          url = "https://api.twitter.com/1.1/geo/id/6416b8512febefc9.json";
      };
      "possibly_sensitive" = 0;
      "retweet_count" = 0;
      retweeted = 0;
      source = "&lt;a href=\"http://twitter.com\" rel=\"nofollow\"&gt;Twitter Web Client&lt;/a&gt;";
      text = "Test http://t.co/kKBrsjf4GO";
      truncated = 0;
      user =         {
          "contributors_enabled" = 0;
          "created_at" = "Sat Jan 29 11:30:22 +0000 2011";
          "default_profile" = 0;
          "default_profile_image" = 0;
          description = "You can't just grow a sexy beard. You either have one, or you don't..:";
          entities =             {
              description =                 {
                  urls =                     (
                  );
              };
          };
          "favourites_count" = 0;
          "follow_request_sent" = "&lt;null&gt;";
          "followers_count" = 17;
          following = "&lt;null&gt;";
          "friends_count" = 47;
          "geo_enabled" = 1;
          id = 244472426;
          "id_str" = 244472426;
          "is_translation_enabled" = 0;
          "is_translator" = 0;
          lang = en;
          "listed_count" = 0;
          location = "";
          name = "Christopher Fuertes";
          notifications = "&lt;null&gt;";
          "profile_background_color" = 1A1B1F;
          "profile_background_image_url" = "http://pbs.twimg.com/profile_background_images/558638885/559647_3164538518462_1415356240_32122022_1669491008_n.jpg";
          "profile_background_image_url_https" = "https://pbs.twimg.com/profile_background_images/558638885/559647_3164538518462_1415356240_32122022_1669491008_n.jpg";
          "profile_background_tile" = 1;
          "profile_banner_url" = "https://pbs.twimg.com/profile_banners/244472426/1352679509";
          "profile_image_url" = "http://pbs.twimg.com/profile_images/2838158026/56ed90e6ccc6c35cc41a1a8a41db312e_normal.jpeg";
          "profile_image_url_https" = "https://pbs.twimg.com/profile_images/2838158026/56ed90e6ccc6c35cc41a1a8a41db312e_normal.jpeg";
          "profile_link_color" = 960E20;
          "profile_sidebar_border_color" = FFFFFF;
          "profile_sidebar_fill_color" = 252429;
          "profile_text_color" = 666666;
          "profile_use_background_image" = 1;
          protected = 0;
          "screen_name" = calsofer;
          "statuses_count" = 1;
          "time_zone" = "Kuala Lumpur";
          url = "&lt;null&gt;";
          "utc_offset" = 28800;
          verified = 0;
      };
  }
  )
  </code></pre>
  
  <p>And heres my code for passing it to web service:</p>
  
  <pre><code> NSLog(@"UserDefault Tweets: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_TWEETS_KEY]);
  NSLog(@"UserDefault Date Created: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_DATE_CREATED_KEY]);
  NSLog(@"UserDefault Country: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_COUNTRY_KEY]);
  NSLog(@"UserDefault Place Name: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_PLACE_NAME_KEY]);
  NSLog(@"UserDefault Latitude: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_LATITUDE_KEY]);
  NSLog(@"UserDefault Longtitude: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_LONGITUDE_KEY]);
  NSLog(@"UserDefault Media URL: %@", [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_FEED_MEDIA_URL_KEY]);
  
  NSDictionary * dict = [NSDictionary dictionaryWithObject:[NSArray arrayWithObjects: [[NSUserDefaults standardUserDefaults] valueForKey:SESSION_TOKEN], [NSString stringWithFormat:@"%d", track_id], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_TWEETS_KEY], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_DATE_CREATED_KEY], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_COUNTRY_KEY], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_PLACE_NAME_KEY], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_LATITUDE_KEY], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_LONGITUDE_KEY], [[NSUserDefaults standardUserDefaults] valueForKey:TWITTER_FEED_MEDIA_URL_KEY],TWITTER_PROVIDER, nil]
                                                    forKey:[NSArray arrayWithObjects:SESSION_TOKEN, @"track_id", @"message",@"date_created",@"country",@"place_name",@"latitude",@"longitude",@"media_url",@"provider_name", nil]];
  
  [webService postRequestFromUrl:[NSString stringWithFormat:@"%@%@", ROOT_SERVER_URL, SAVE_DATA_FEEDS] withDictionary:dict];
  </code></pre>
  
  <p>but I'm getting a error in doing that. the error is:</p>
  
  <p><img src="https://i.stack.imgur.com/ZgEZz.png" alt="enter image description here"></p>