Fatal error: Uncaught Error: Interface "Psr\Container\ContainerInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/symfony/service-contracts/ServiceProviderInterface.php:24 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/symfony/service-contracts/ServiceProviderInterface.php on line 24