Fatal error: Uncaught Error: Class "yii\base\Event" not found in /home/cooperativamaism/public_html/staging/vendor/craftcms/cms/src/events/UserGroupEvent.php:19 Stack trace: #0 {main} thrown in /home/cooperativamaism/public_html/staging/vendor/craftcms/cms/src/events/UserGroupEvent.php on line 19