Fatal error: Uncaught Error: Interface "Illuminate\Contracts\Validation\Rule" not found in /var/www/html/repo/school-infix-v6.0/app/Rules/UniqueStaff.php:9 Stack trace: #0 {main} thrown in /var/www/html/repo/school-infix-v6.0/app/Rules/UniqueStaff.php on line 9