Fatal error: Uncaught Error: Class "yii\helpers\Html" not found in /users/quirl/www/filemanager/spark/protected/humhub/modules/file/widgets/views/uploadButton.php:10 Stack trace: #0 {main} thrown in /users/quirl/www/filemanager/spark/protected/humhub/modules/file/widgets/views/uploadButton.php on line 10