Fatal error: Uncaught Error: Class "Drupal\Core\Extension\ModuleExtensionList" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Installer/InstallerModuleExtensionList.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Installer/InstallerModuleExtensionList.php on line 10