Fatal error: Uncaught Error: Class 'Doctrine\ORM\Id\AbstractIdGenerator' not found in C:\Apache24\htdocs\InvoiceTracking\vendor\doctrine\orm\lib\Doctrine\ORM\Id\BigIntegerIdentityGenerator.php:29 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\InvoiceTracking\vendor\doctrine\orm\lib\Doctrine\ORM\Id\BigIntegerIdentityGenerator.php on line 29