After several attempts on Getting Lets Encrypt to work on PBXact and FreePBX on SNG7 I finally got it to work with a grade of A on SSLLABS.com instead of an F.
1.) Install SNG7-1710 on machine
2.) At first login - Do Not Activate the deployment yet. — do yum update
3.) After that is complete reboot system
4.) login and Activate the deployment
5.) fwconsole --edge ma upgrade certman
5.) SSH into the box and delete the following directory /etc/asterisk/keys/_account/ ( just the _account directory
cd /etc/asterisk/keys/
rm -r _account
6.) In Sysadmin Pro if you have it - goto DNS and setup your FQDN
7.) Proceed with the LetsEncrypt procedure on issuing your certificate.
Hope this helps anyone with those annoying errors… Tried everything else and just gave up and it looks like this has been working flawlessly for me.
Update 12/23/2017
****If Installing from latest ISO ******* No need to follow the directions above