Hello again: I spent two days to understand (and check it wisely) I forgot to add acme.sh when I run my installation, so I followed this guide: https://www.howtoforge.com/tutorial/securing-ispconfig-3-with-a-free-lets-encrypt-ssl-certificate/ My ISPConfig website is up and running, responding on 8080 port. My "user website" is up and running responding on 80 port. DNS changed to point server IP on the registar. The command `hostname -f` gives me the full URL of my server (servername.companyname.ext) I forgot to add acme.sh in my first installation (cloudflare option). But I decided to try Let's Encrypt. So I used the wget command to install acme and then runned ispconfig_update.sh with reconfigure_services=yes to try to add a cert. My server URL port 80 is not responding (that's normal, it's running on 8080) so the update forces me to create a self-signed cert. Now my ISPConfig URL runs on https but with warnings of self-signed cert. After that I selected in the ISPConfig panel the options SSL and Let's Encrypt options for my "user website" (userURL.com). The process finished without errors or warnings. I checked my userURL.com and is working without SSL. I checked my https://userURL.com and it tells me the error : ERR_CONNECTION_REFUSED I readed https://www.howtoforge.com/community/threads/lets-encrypt-error-faq.74179/ but my server doesn't have the folder /var/log/letsencrypt I runned the command openssl s_client -servername example.io -connect example.io:443 </dev/null The result: 139855801173120:error:0200206F:system library:connect:Connection refused:../crypto/bio/b_sock2.c:110: 139855801173120:error:2008A067:BIO routines:BIO_connect:connect error:../crypto/bio/b_sock2.c:111: connect:errno=111 Any idea to check what's happening here? EDIT 1 : first guess: should the acme.sh be installed by the root user? because as I can see that didn't happen in my system: #LOG_FILE="/home/not_root_user/.acme.sh/acme.sh.log" EDIT 2: same result after reinstalling acme.sh with a previous "sudo su" command, then re-updating ISPConfig, then try to create the SSL and Let'sEncrypt config for my "userURL.com"