Fatal error: Uncaught Error: Class 'Symfony\Component\DependencyInjection\Extension\Extension' not found in /home/eberhardschwarze/public_html/vendor/contao/calendar-bundle/src/DependencyInjection/ContaoCalendarExtension.php:23 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/contao/calendar-bundle/src/DependencyInjection/ContaoCalendarExtension.php on line 23