First of all, I want to say that it is awesome that 3CX incorporated Let's Encrypt. It looks like if you let 3CX create your own FQDN a Let's Encrypt certificate is generated, but if you specify your own FQDN the installer wants you to provide the cert. It would be nice if you also had the option to let 3CX create a Let's Encrypt cert using your own FQDN as well. I just used https://zerossl.com to create a certificate and then provided that to the installer. I just noticed this in my event log: But in looking at my certificate, it doens't appear to have been renewed: Now being that I used my own FDQN and manually supplied the certificate I wouldn't expect 3CX to manage it. But it appears it is trying to manage/renew it and logging it, albeit incorrectly.