Fatal error: Uncaught Error: Class 'Symfony\Component\Form\AbstractExtension' not found in D:\workspaces\liZiPingBack\vendor\symfony\form\Extension\HttpFoundation\HttpFoundationExtension.php:21 Stack trace: #0 {main} thrown in D:\workspaces\liZiPingBack\vendor\symfony\form\Extension\HttpFoundation\HttpFoundationExtension.php on line 21