Replacing revoked SSL Certs, The server could not connect to the domain:: Server failure at resolver

Running an Apache Server on Ubuntu 12.04. Server was previously running fine and resolving to the domain with GoDaddy Certs. I had revoked the certs and was hoping to get this back up with letsencrypt certs. I’ve tried various ways of installing them letsencrypt-auto -standalone, apache, webroot, but all of them give me a fail to connect to the domain.

The domain records are there and have been working for resolution for years with the Godaddy certs.
We have a Fortigate firewall that port forwards the external ip address to the internal ip address of the server. Is there something I’m missing?

Can you reach the domain in a normal browser ?

Are you forcing https - which now has revoked certificates ?

If you provide the domain name it may help people provide assistance.