A complete reinstall… still don’t understand what happened…
Yes this was this plugin. The wordpress version is up to date. I noticed that when accessing using https://leonardo-labs.fr no debug information is displayed. But using http://leonardo-labs.fr there are debug messages. I didn’t change the server setup for month on my web hosting configuration…
(note that the link you indicate to test the site provides inaccurate information, as it says that I’m using WP4.8 and the current used version is 4.9.4)
