- Inbound/Outbound TCP Ports - 55443 and 55000 on Server Firewall
- You need to go to API Access Inside Opensrs and Add Server IP to OpenSRS Firewall
Sometimes, if you are on a custom IP on the server, the network connection comes from a different IP Address to what's reported by PHPINFO(). So, to determine this, ask your server admin, whom can do this by using the following linux bash command:-
telnet rr-n1-tor.opensrs.net 55000
55443 is an SSL port, so you can't test it with telnet, but it might connect and give an escape command.
On 55000 it will give you the reason why you can't connect.
It takes up to an hour for OpenSRS to update their firewall rules, so wait patiently and the WHMCS Domain Connection ERROR will vanish when it works again.