When renewing your SSL certificate using the certbot -renew command, you got an error saying “Attempting to renew cert (yourdomain.com) from /etc/letsencrypt/renewal/yourdomain.com/conf produced an unexpected error: Problem binding to port 443: Could not bind to IPV4 or IPV6.. Skipping.”. This error occurs because some of your apps are using the port 443 in https module.
There are two ways on solving this problem.
Solution 1: Turning Off Apache Server then Renew Certbot
The fastest approach is by turning off your apache server and do the certbot renew. Then turning it back again. But this solution will make your websites connected to your server becomes unavailable.
On CentOS, here is the sample command that you can use:
apachectl stop certbot renew apachectl start
Solution 2: Using new Challenge that will not use Port 443
On CentOS, you can use the following command:
certbot --standalone-supported-challenges http-01 -d yourdomain.cc -d www.yourdomain.cc
That’s it. Hope this solution help you with your problem. I am not expert on this field, so sorry for using other name methodology or something.