Fatal error: Uncaught Error: Class 'Doctrine\ORM\Id\AbstractIdGenerator' not found in D:\workspaces\liZiPingBack\vendor\doctrine\orm\lib\Doctrine\ORM\Id\UuidGenerator.php:21 Stack trace: #0 {main} thrown in D:\workspaces\liZiPingBack\vendor\doctrine\orm\lib\Doctrine\ORM\Id\UuidGenerator.php on line 21