Fatal error: Uncaught Error: Class 'OAuth\OAuth2\Service\AbstractService' not found in C:\xampp7\htdocs\edgpens\vendor\lusitanian\oauth\src\OAuth\OAuth2\Service\Facebook.php:14 Stack trace: #0 {main} thrown in C:\xampp7\htdocs\edgpens\vendor\lusitanian\oauth\src\OAuth\OAuth2\Service\Facebook.php on line 14