Fatal error: Uncaught Error: Class 'yii\helpers\Html' not found in /opt/lampp/htdocs/123playnow-external/vendor/dmstr/yii2-adminlte-asset/example-views/yiisoft/yii2-app/layouts/header.php:10 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/123playnow-external/vendor/dmstr/yii2-adminlte-asset/example-views/yiisoft/yii2-app/layouts/header.php on line 10