error after updating whmcs integration plugin


I updated the whmcs wp integration plugin to version 1.3 and now on certain pages in the client area i get the following error:

Sorry this doesn't look like a WHMCS site at [] 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'm not using ssl and all specified links in wordpress and whmcs are correct for http://

I have the whmcs template 'six' active and your changelog states fully compatible with whmcs 6 so I'm a bit baffled as to the cause of this issue?

I am running whmcs 6.1 and wordpress 4.3.1

Thanks in advance