Fatal error: Uncaught Error: Using $this when not in object context in /mnt/disk1/hosted/cuadro_mando/vendor/yiisoft/yii2/views/_dropColumns.php:3 Stack trace: #0 {main} thrown in /mnt/disk1/hosted/cuadro_mando/vendor/yiisoft/yii2/views/_dropColumns.php on line 3