title: Facebook Needs the JSON php extension?>
body: <p>I am trying to use FB login. I have used the same code for other websites and it works fine. But  only one domain it returns a fatal error. </p>
  
  <blockquote>
    <p>Fatal error: Uncaught 'Exception' with message 'Facebook needs the
    JSON PHP extension' in
    /var/www/vhosts/domain.com/httpdocs/base_facebook.php:22 Stack trace
     /var/www/vhosts/domain.com/httpdocs/facebook.php:18 require_once()#1 ....</p>
  </blockquote>