Setting form crash

I been try use this module today but seams doesn't work. Block do not show nothing expect title and one bullet of list. On configuration page I have:

warning: call_user_func_array() expects parameter 1 to be a valid callback, function 'progress_tracker_settings_form' not found or invalid function name in /home/mks24/public_html/www/includes/form.inc on line 377.

I use Zen theme if this have any meaning.