Fatal error: Uncaught Error: Using $this when not in object context in /var/www/binary/vendor/dmstr/yii2-adminlte-asset/example-views/yiisoft/yii2-app/layouts/content.php:8 Stack trace: #0 {main} thrown in /var/www/binary/vendor/dmstr/yii2-adminlte-asset/example-views/yiisoft/yii2-app/layouts/content.php on line 8