Fatal error: Uncaught Error: Class "Drupal\Core\Installer\InstallerKernel" not found in /usr/www/users/zipse/website/web/core/includes/errors.inc:315 Stack trace: #0 /usr/www/users/zipse/website/web/core/includes/errors.inc(123): _drupal_get_error_level() #1 /usr/www/users/zipse/website/web/core/includes/bootstrap.inc(202): error_displayable() #2 /usr/www/users/zipse/website/web/core/includes/bootstrap.inc(186): _drupal_exception_handler_additional() #3 [internal function]: _drupal_exception_handler() #4 {main} thrown in /usr/www/users/zipse/website/web/core/includes/errors.inc on line 315