WHMCS Integration: Failure when receiving data from the peer

I am currently using the WHMCS Integration plugin and followed the install steps however when i click on the Wordpress page i am planning to have WHMCS work on the following error is displayed:

WHMCS Integration: Failure when receiving data from the peer

My install is as follows:
WordPress install at root of server and then WHMCS installed in a separate directory on root
root = Wordpress
root/whcms = WHCMS Install

So domain like:

http://www.mysite.co.uk - Wordpress
http://www.mysite.co.uk/whcms - WHCMS portal
http://www.mysite.co.uk/client portal - WP integration page

I have copy and past the URL from WHCMS settings portal and added that to the plugin and i have gone over the steps a couple of times and done a search online but can't find an answer to this error message.

WHCMS portal works all ok so i know thats online and responding

Any suggestions?