Fatal error: Uncaught Error: Interface 'Symfony\Contracts\Service\ServiceSubscriberInterface' not found in /var/www/alldocs/home/sdoehner/webtest/simplesamlphp_idp/vendor/symfony/dependency-injection/ServiceSubscriberInterface.php:21 Stack trace: #0 {main} thrown in /var/www/alldocs/home/sdoehner/webtest/simplesamlphp_idp/vendor/symfony/dependency-injection/ServiceSubscriberInterface.php on line 21