Fatal error: Uncaught Error: Class "Drupal\FunctionalTests\Installer\ConfigAfterInstallerTestBase" not found in /home/qcsvlel/www/core/tests/Drupal/FunctionalTests/Installer/StandardInstallerTest.php:12 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/tests/Drupal/FunctionalTests/Installer/StandardInstallerTest.php on line 12