If you want to use the wp_category_checklist on pages that also non-admin users access. You have to include the following php:
<? require_once(ABSPATH.'wp-admin/includes/template.php'); ?>
Credit to Majick!
If you want to use the wp_category_checklist on pages that also non-admin users access. You have to include the following php:
<? require_once(ABSPATH.'wp-admin/includes/template.php'); ?>
Credit to Majick!