Fatal error: Uncaught Error: Interface 'Contao\CoreBundle\OptIn\OptInInterface' not found in /home/benjamincb/demos/acdg-site/vendor/contao/core-bundle/src/OptIn/OptIn.php:19 Stack trace: #0 {main} thrown in /home/benjamincb/demos/acdg-site/vendor/contao/core-bundle/src/OptIn/OptIn.php on line 19