Warning: in_array() expects parameter 2 to be array, string given in /home/careerv/...

I get this message when I preview a page on the course I am creating...

Warning: in_array() expects parameter 2 to be array, string given in /home/careerv/careerveneer.com/10in15/wp-content/plugins/coursepress/includes/unit-modules/checkbox_input.php on line 130

How do I fix this?