Fatal error: Uncaught Error: Interface "Symfony\Component\Config\ResourceCheckerInterface" not found in /srv/disk1/2895578/www/whittonphotographicclub.org.uk/concrete/vendor/symfony/config/Resource/SelfCheckingResourceChecker.php:24 Stack trace: #0 {main} thrown in /srv/disk1/2895578/www/whittonphotographicclub.org.uk/concrete/vendor/symfony/config/Resource/SelfCheckingResourceChecker.php on line 24