Fatal error after upgrading Coursepress and Smush.it

Can't get to the website because of the following fatal error:
Fatal error: Call to a member function is_main_query() on a non-object in /home/content/87/11283687/html/portal/wp-content/plugins/events-and-bookings/lib/default_filters.php on line 122

Last thing done was upgrading Courepress and Smush.it plugins to latest version.

Thanks
Shireen