Fatal error: Uncaught Error: Class "Drupal\Tests\content_translation\Functional\ContentTranslationUITestBase" not found in /home/www/drupal8/test/core/modules/user/tests/src/Functional/UserTranslationUITest.php:12 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/user/tests/src/Functional/UserTranslationUITest.php on line 12