Fatal error: Uncaught Error: Class 'yii\db\Migration' not found in /home/wittyly/public_html/live/hr-witty/migrations/m201026_051858_alter_col_created_at_on_property_group_tbl.php:7 Stack trace: #0 {main} thrown in /home/wittyly/public_html/live/hr-witty/migrations/m201026_051858_alter_col_created_at_on_property_group_tbl.php on line 7