Fatal error: Uncaught Error: Class 'Symfony\Component\Form\AbstractExtension' not found in D:\workspaces\liZiPingBack\vendor\symfony\doctrine-bridge\Form\DoctrineOrmExtension.php:18 Stack trace: #0 {main} thrown in D:\workspaces\liZiPingBack\vendor\symfony\doctrine-bridge\Form\DoctrineOrmExtension.php on line 18