Hi, I tried a lot of things, but to no avail. I have ISPConfig 3.1.13 with Nginx and PHP 7 on a Debian GNU/Linux 9.5. Two sites are running fine with Let's Encrypt. The third it will not attempt to make create a Let's Encrypt for. I know this because the /var/log/letsencrypt log will not tail anything new. Also in the letsencrypt/live dir there are only the cert dirs of the other two sites. I suspect it has to do with two of them being subdomains. De https versions then redirects to the first site made because it undo's the SSL setting when saving. When I use only SSL on, no let's encrypt, I get the local cert and can allow for the exception and see the right site. I have, dots replaced to allow for posting, www-adomain-com (LE works), x-bdomain-com (LE works) and y-bdomain-com (LE not working). All three are made for different clients. All three have same IP configured. All DNS configurations are good. I tried deleting and recreating the site in Ispconfig and retried creating and enabling Let's Encrypt, it seems to have no effect. Also vhost looks normal, but obviously missing all SSL statements.
Hi Till, thank you for replying. I already have been through all of that before, none if that helps. ISPconfig does not attempt to create Let's encrypt, there is also no error in the ispconfig cron.log. cron.log only says this when I check Let's encrypt for this site: Tue Jan 15 12:47:01 CET 2019 Tue Jan 15 12:47:01 CET 2019 finished.
Did you disable the lets encrypt check under system > server config > web and tried to activate Let's encrypt in the website again? When your server is behind a NAT router, then you must disable the check.
Take a look at the letsencrypt.log to find out why let's encrypt is not able to get an SSL cert for that domain.