Fatal error: Uncaught Error: Class 'yii\db\Migration' not found in /home/wittyly/public_html/live/hr-witty/migrations/m220217_052629_add_is_private_column_to_schedule_event_table.php:8 Stack trace: #0 {main} thrown in /home/wittyly/public_html/live/hr-witty/migrations/m220217_052629_add_is_private_column_to_schedule_event_table.php on line 8