Fatal error: Uncaught Error: Class "Drupal\Core\Form\FormBase" not found in /home/qcsvlel/www/core/modules/file/tests/file_test/src/Form/FileTestSaveUploadFromForm.php:18 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/file/tests/file_test/src/Form/FileTestSaveUploadFromForm.php on line 18