Fatal error: Uncaught Error: Class 'Illuminate\Database\Migrations\Migration' not found in /home/eurjchem/public_html/lib/pkp/classes/migration/upgrade/PKPv3_3_0UpgradeMigration.inc.php:20 Stack trace: #0 {main} thrown in /home/eurjchem/public_html/lib/pkp/classes/migration/upgrade/PKPv3_3_0UpgradeMigration.inc.php on line 20