Fatal error: Uncaught Error: Class "Doctrine\DBAL\Event\SchemaEventArgs" not found in E:\xampp\htdocs\stms\vendor\doctrine\dbal\src\Event\SchemaAlterTableAddColumnEventArgs.php:19 Stack trace: #0 {main} thrown in E:\xampp\htdocs\stms\vendor\doctrine\dbal\src\Event\SchemaAlterTableAddColumnEventArgs.php on line 19