Fatal error: Uncaught Error: Class 'Illuminate\Database\Migrations\Migration' not found in /home/caistbuw/public_html/database/migrations/2019_08_08_162302_add_sub_units_related_fields.php:7 Stack trace: #0 {main} thrown in /home/caistbuw/public_html/database/migrations/2019_08_08_162302_add_sub_units_related_fields.php on line 7