So it seems the plugin got deactivated after I did an upgrade. I was able to resolve this by manually activating the plugin through a php script - since I couldn't do it through the admin.
Now, however, it is working but with my debugger on I am getting the following error message:
Warning: Missing argument 2 for wpcf7_add_shortcode() in ....../wp-content/plugins/contact-form-7/includes/shortcodes.php on line 179