My domain is: nubes-leporum.ddns.net
I ran this command: sudo letsencrypt renew
It produced this output: …Attempting to renew cert (nubes-leporum.ddns.net) from /etc/letsencrypt/renewal/nubes-leporum.ddns.net.conf produced an unexpected error: Failed authorization procedure. nubes-leporum.ddns.net (tls-sni-01): urn:ietf:params:acme:error:unknownHost :: The server could not resolve a domain name :: No valid IP addresses found for nubes-leporum.ddns.net. Skipping.
All renewal attempts failed. The following certs could not be renewed:
/etc/letsencrypt/live/nubes-leporum.ddns.net/fullchain.pem (failure) …
My web server is (include version): apache2
The operating system my web server runs on is (include version): ubuntu 16.04 LTS
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don’t know): yes
I’m using a control panel to manage my site (no, or provide the name and version of the control panel): no