Fatal error: Uncaught Error: Class "Drupal\Core\Form\FormBase" not found in /home/tubu/public_html/Drupal_CMS/cms/vendor/drupal/recipe_installer_kit/src/Form/SiteNameForm.php:14 Stack trace: #0 {main} thrown in /home/tubu/public_html/Drupal_CMS/cms/vendor/drupal/recipe_installer_kit/src/Form/SiteNameForm.php on line 14