WHMCS integrator error: This doesnt' look like a WHMCS site

The URL is http://www.legalnursenetwork.com/web-services/
When i went to run a test transaction through the integrated plugin i got:

Sorry this doesn't look like a WHMCS site at [https://legalnursenetwork.com/web-provisioning/] Make sure your WHMCS Integration settings are pointing to the correct URL and that the WHMCS site is set for the Portal template in Setup | General.

I read another post and ran the W3c's validator.
http://validator.w3.org/check?uri=http%3A%2F%2Flegalnursenetwork.com%2Fweb-provisioning%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

I find it very hard to believe that 2 "&" symbols which are default in the template this was designed for is the cause of the error.

The site URL and remote URL are both https://

Everything works fine until i try to checkout.

Any assistance would be appreciated