Fatal error: Uncaught Error: Class "Drupal\Core\Form\FormBase" not found in /home/fnbrshareacopy/public_html/modules/contrib/field_group/src/Form/FieldGroupAddForm.php:18 Stack trace: #0 {main} thrown in /home/fnbrshareacopy/public_html/modules/contrib/field_group/src/Form/FieldGroupAddForm.php on line 18