Fatal error: Uncaught Error: Interface "Symfony\Contracts\Service\ContainerProviderInterface" not found in C:\xampp\htdocs\regenbogenhof\vendor\symfony\service-contracts\ContainerAwareInterface.php:17 Stack trace: #0 {main} thrown in C:\xampp\htdocs\regenbogenhof\vendor\symfony\service-contracts\ContainerAwareInterface.php on line 17