404. That’s an error.
The requested URL /add?feedurl=http%3A%2F%2Freactup.fr%2Ffiles%2Frss%2Frss_reactup.xml was not found on this server. That’s all we know.
/add?feedurl=http%3A%2F%2Freactup.fr%2Ffiles%2Frss%2Frss_reactup.xml