Fatal error: Uncaught Error: Class "yii\base\Widget" not found in /users/quirl/www/filemanager/spark/protected/humhub/widgets/mails/MailButtonList.php:17 Stack trace: #0 {main} thrown in /users/quirl/www/filemanager/spark/protected/humhub/widgets/mails/MailButtonList.php on line 17