Facebook Invite/Request does not display correctly for iOS

Question

I am trying to implement facebook invites using the following code (from the Facebook documentation here).

    NSMutableDictionary* params =   [NSMutableDictionary dictionaryWithObjectsAndKeys:nil];
[FBWebDialogs presentRequestsDialogModallyWithSession:nil
                                              message:[NSString stringWithFormat:@"Can you beat my highscore of %@ points on Footy Face-Off?", formattedString]
                                                title:nil
                                           parameters:params
                                              handler:^(FBWebDialogResult result, NSURL *resultURL, NSError *error) {
                                                  if (error) {
                                                      // Case A: Error launching the dialog or sending request.
                                                      NSLog(@"Error sending request.");
                                                  } else {
                                                      if (result == FBWebDialogResultDialogNotCompleted) {
                                                          // Case B: User clicked the "x" icon
                                                          NSLog(@"User canceled request.");
                                                      } else {
                                                          NSLog(@"Request Sent.");
                                                      }
                                                  }}];

The problem is that instead of displaying a dialog such as in the Facebook docs, it is instead displaying this.

Sending a request does not do anything either, even though I am logged in to facebook and have the required permissions. Ultimately what I am asking, is what am I doing wrong that I'm not generating a request such as from the Facebook docs. Any help or suggestions are greatly appreciated.