Error from Plugin

This is a nice plugin, however, when I activate it, it throws the following error on the page.

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘your_function’ not found or invalid function name in /home1/fordyced/public_html/Troop92Holliday/wp-includes/plugin.php on line 524

Can that be fixed?