Fatal error: Class 'Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationPass' not found in /home/optinadmin/callaghaninnovation.optin.co.nz/concrete/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/DependencyInjection/MergeExtensionConfigurationPass.php on line 23