Localhost is down

I had Drupal 8.2.4 running under Ubunutu 16.04. Now, I get next error message when launching localhost or localhost/user or localhost/phpinfo.php, etc… : “handle($request); $response->send(); $kernel->terminate($request, $response); “ Apache 2.4.18 is up and running. Any idea how to fix it? Drupal version:  Drupal 8.x […]