Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
My domain is: admin.rstunlimited.us/
I ran this command: letsencrypt-auto renew
It produced this output: Problem binding to port 443: Could not bind to IPv4 or IPv6
My web server is (include version): Sentora
The operating system my web server runs on is (include version): Ubuntu 14.04.5 LTS
My hosting provider, if applicable, is: DreamHost Cloud
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
Has something changed how letsencrypt processes cert updates in the last couple of months? I have four domains using SSL. Three were renewed fine a couple of months ago, but when I ran the renew command today the "Problem binding to port 443: Could not bind to IPv4 or IPv6
" error message appeared for admin.rstunlimited.us/.