If cert.int-x3.letsencrypt.net is unreachable, this could indicate a problem with the redirection settings across its different versions. To access the site, try using one of the links below:

http://cert.int-x3.letsencrypt.net https://cert.int-x3.letsencrypt.net

Or return to the current status page of cert.int-x3.letsencrypt.net.