Fatal error: Uncaught Error: Class 'yii\db\Migration' not found in /home/wittyly/public_html/live/hr-witty/migrations/m210127_000815_alter_scheduled_events_add_org_id_column.php:8 Stack trace: #0 {main} thrown in /home/wittyly/public_html/live/hr-witty/migrations/m210127_000815_alter_scheduled_events_add_org_id_column.php on line 8