A fatal error is usually thrown up when you haven't installed the Extension Works framework.
This additional download is mandatory for all of our extensions.
You should see a notification in the Wordpress admin plugins area highlighted by a yellow banner at the top of the page.
It will say "INSTALL THE EXTENSION WORKS FRAMEWORK"
THE EXAMPLE USED SAYS "INSTALL THE EXTENSION WORKS UPDATER PLUGIN"
If you log a Support ticket we can supply you with the files for the Extension Works Framework.