When I load https://lingualibre.org, I got a warning from Firefox saying that the website is unsafe. This is due to the fact that the certifcate expired (expiration date is 2020-08-27). Could someone renew it as soon as possible?
Someone renewed it to the end of November 2020. Thanks to him/her. I think you could let this ticket open until an automated tool has been implemented in order to renew the certificate automatically.
There is now an automatic renewal with Let’s Encrypt+certbot, and the two renewal since were correctly done one month before the expiration.
I just let this task open to remember to setup it again on the near-future server.
More details: there are currently 3 independent certificates: lingualibre.org, www.lingualibre.org, lingualibre.fr. On the webserver, the 2 latter are configured to redirect to the former.