Error 22/500 when accessing domains in Client Area

[Brewer Harry]

Background - using wordpress theme with WHMCS Bridge.

Registrar - Synergy Wholesale

 

When transferring or registering a new domain, an error is created when trying to view said domain in client area via the link: http://example.com/whmcs-bridge/clientarea/?action=domains

 

The error received is:

 

Warning: HTTP Error:22/The requested URL returned error: 500 Internal Server Error at http://example.com/whmcs/clientarea.php?action=domains&systpl=arkahostwhmcs in /home/rootfolder/public_html/example.com

 

I have had the wordpress theme developer explore the error for me, but he advises it is a WHMCS issue. I have explored extensively, but I am unable to identify the problem.

 

One thing I have noted, is that the error seems to appear when an order status goes from pending/transfer pending to ACTIVE.

 

If anyone can provide some advice, I would greatly appreciate it.

Thank