Fatal error: Call to a member function is_main_query() on a non-object in /home/username/public_html

All of a sudden we saw this:
Fatal error: Call to a member function is_main_query() on a non-object in /home/everythi/public_html/wp-content/plugins/events-and-bookings/lib/default_filters.php on line 122

I deleted the plugin from ftp as we could not log in. Tried it again both with individual and network activation on this website and get the same error.