Warning: array_map(): Argument #2 Issue

Just recently the following warning message began to appear on the Events List (Appearances) at http://tripledoserocks.com/events/event/

Warning: array_map(): Argument #2 should be an array in /home/tripledose/www/www/wp-includes/category-template.php on line 1158.

Been researching to find out how to fix, but can’t find the solution.

Help!

https://wordpress.org/plugins/event-organiser/