WHMCS Integration plugin error

Hello There,

I just purchased a membership so I can download the WHMCS Integration Plugin.

I installed the plugin in WordPress but when I attempt to activate the plugin I get the following error:

Plugin could not be activated because it triggered a fatal error.

There are no errors in the error_log file. I'm running WordPress 3.7.1 and WHMCS 5.2.14

Any help would be appricated.