Updating Appointments+ to version 1.7.1 kills my site!

Hi there,

If I update the Appointments+ plugin to 1.7.1 my site dies. I know that this plugin is the cause. What I mean by this is that this is the only plugin that I need to update. Before the update, the site works fine, after the update the only things that I can see on the site is the theme header and footer - all of the contents of pages and posts is not being printed to the page.

I am using the most up-to-date X Theme with Cornerstone page builder.

Please help me out, I would like to update to make use of the new features, but cannot at this point!

I have cleared caches and transients from the site after the failed update and have had to restore from a backup.