Fatal error: Uncaught Error: Class "yii\validators\Validator" not found in /users/quirl/www/filemanager/spark/protected/humhub/modules/ui/form/validators/IconValidator.php:24 Stack trace: #0 {main} thrown in /users/quirl/www/filemanager/spark/protected/humhub/modules/ui/form/validators/IconValidator.php on line 24