Fatal error: Uncaught Error: Class "Symfony\Component\Translation\Extractor\Visitor\AbstractVisitor" not found in C:\AppServ\Apache\2.4.58\htdocs\sets\vendor\symfony\translation\Extractor\Visitor\ConstraintVisitor.php:22 Stack trace: #0 {main} thrown in C:\AppServ\Apache\2.4.58\htdocs\sets\vendor\symfony\translation\Extractor\Visitor\ConstraintVisitor.php on line 22