Fatal error: Uncaught Error: Class "Twig\Extension\AbstractExtension" not found in I:\www\frameworks\Symfony\doctrine\vendor\symfony\twig-bridge\Extension\SerializerExtension.php:20 Stack trace: #0 {main} thrown in I:\www\frameworks\Symfony\doctrine\vendor\symfony\twig-bridge\Extension\SerializerExtension.php on line 20