WHMCS 6.3.1 no longer working

[CCJ]

I bought a permanent license about 10 years ago, and still using in with WHMCS 6.1

However, a few days ago, it's no longer working as it is not connection to the WHMCS Licensing Server.

 

Connection Error

WHMCS has not been able to verify your license for the last few days.

Before you can access your WHMCS Admin Area again, the license needs to be validated successfully. Please check & ensure that you don't have a firewall or DNS rule blocking outgoing connections to our website.

Error below when performing connection test. My webhost company was telling me that this is due to recent changes to WHMCS, and I need to upgrade my WHMCS.  Is this true?
 

Testing Connection to whmcs.com...
URL resolves to 104.20.36.75

Error: The IP whmcs.com is resolving to the wrong IP. Someone on your server is trying to bypass licensing. You'll need your host to investigate and fix.

[bear]

Can't say for sure if your installation isn't compromised or that WHMCS has changed something in the licensing server that broke your really old license, but that IP appears fine for WHMCS. 
 

Quote

10/23/26 06:14:29 dns whmcs.com
Canonical name: whmcs.com
Addresses:
  172.66.151.35
  104.20.36.75

 

[Waqas Ahmed Waseer]

That "resolving to the wrong IP" line is a bit of a red herring. The curltest script compares the lookup against a short list of IPs hardcoded into the script, and that list has gone stale more than once over the years as WHMCS moved its licensing infrastructure. 104.20.36.75 and 172.66.151.35 are exactly what whmcs.com resolves to from anywhere right now, so your server's DNS isn't being hijacked. Don't let anyone "fix" it by pinning whmcs.com to another IP in /etc/hosts; that's the one thing that really would look like a bypass.

What I'd check, in this order:

1. Can the server actually complete an HTTPS request to WHMCS? From SSH as the user WHMCS runs under, run:

curl -sv https://www.whmcs.com/ -o /dev/null

On a box old enough to still run WHMCS 6 (PHP 5.x era), the usual failure is the TLS handshake or an outdated CA bundle, not DNS. If curl from the shell works but PHP's curl doesn't, the PHP build's OpenSSL is the problem.

2. Log in to your account at whmcs.com and look at the license itself: status Active, and the Valid Domains/IPs/Directory match where the install lives now. If the server IP changed recently, a reissue from the client area clears that.

3. If both of those are fine, open a ticket with WHMCS licensing, give them the license key, and ask straight out whether 6.x installs can still validate against the current licensing servers. They can see the failed check attempts on their side, which beats guessing.

On the upgrade question: whatever the root cause turns out to be, 6.x is many years past end of life and only runs on PHP versions that stopped getting security fixes a long time ago, so plan the upgrade either way. With an owned license, check whether your Support & Updates is still active; if it lapsed, you'll need to renew it before you can download current versions. Do the jump on a copy of the site and database first, since going from 6 to current means moving through several major versions and PHP versions, and any custom templates or old modules will need checking along the way.

[bear]

1 hour ago, Waqas Ahmed Waseer said:

check whether your Support & Updates is still active

That seems unlikely, with the product itself being EOL'ed almost 10 years ago. Before they ended the support and updates "product",  it was a fairly expensive thing. Though not impossible they bought a pile of them, I'd think that's not plausible, especially since they'd likely have updated since if they could have. Maybe.