Fatal error: Uncaught Error: Interface 'Doctrine\Common\Collections\Collection' not found in /home/almasai/www/people/_old_site/vendor/bundles/FOS/UserBundle/Propel/GroupCollection.php:16 Stack trace: #0 {main} thrown in /home/almasai/www/people/_old_site/vendor/bundles/FOS/UserBundle/Propel/GroupCollection.php on line 16