Fatal error: Uncaught Error: Class 'Contao\CoreBundle\Migration\AbstractMigration' not found in /home/benjamincb/demos/acdg-site/vendor/contao/core-bundle/src/Migration/Version411/MergeWebfontsMigration.php:22 Stack trace: #0 {main} thrown in /home/benjamincb/demos/acdg-site/vendor/contao/core-bundle/src/Migration/Version411/MergeWebfontsMigration.php on line 22