Facebook Error: An error has occurred with the application. Please try again later

My code that was working until yesterday suddenly started throwing errors. I don't know what changed everything. It is also based on code from Facebook Parties Authentication . Also I have mentioned other posts with a similar title, but tried what they mention and no luck.

Here is the code

<?php 

   $app_id = "my app id";
   $app_secret = "my app secret";
   $my_url = "http://apps.facebook.com/myappnamespace";

      

        
        
        
      

    

// Tried https in my_url // Also tried to use direct app path with both http and https and doesn't work. session_start (); $ code = $ _REQUEST ["code"];

   if(empty($code)) {
     $_SESSION['state'] = md5(uniqid(rand(), TRUE)); //CSRF protection
     $dialog_url = "https://www.facebook.com/dialog/oauth?client_id=" 
       . $app_id . "&redirect_uri=" . urlencode($my_url) . "&state="
       . $_SESSION['state'];

     echo("<script> top.location.href='" . $dialog_url . "'</script>");
   }

   if($_REQUEST['state'] == $_SESSION['state']) {
     $token_url = "https://graph.facebook.com/oauth/access_token?"
       . "client_id=" . $app_id . "&redirect_uri=" . urlencode($my_url)
       . "&client_secret=" . $app_secret . "&code=" . $code;

     $response = file_get_contents($token_url);
     $params = null;
     parse_str($response, $params);

     $graph_url = "https://graph.facebook.com/me?access_token=" 
       . $params['access_token'];

     $user = json_decode(file_get_contents($graph_url));
     echo("Hello " . $user->name);
   }
   else {
     echo("The state does not match. You may be a victim of CSRF.");
   }

 ?>