Plus/Minus icons do not change

When clicking the plus icon on the knowledge base, the icon does not toggle.

There is a 404 being thrown. It looks like the path to the image doesn’t swap out properly, and the element .kbe_category span.switch img has a hardcoded reference to the plus sign.

On initial load the href attribute is:
http://www.example.com/wp-content/plugins/wp-knowledgebase/template/images/kbe_icon-plus.png

when clicked it becomes
http://www.example.com/wp-content/plugins/wp-knowledgebase/template/images/kbe_icon-plus.png/template/images/kbe_icon-minus.png

Inside of the script loaded on the page, it appears the href attributes are incorrect, causing the issue:

jQuery('div.kbe_category > span.switch').click(function () {
            var tree_id = jQuery(this).parent().attr('id');
            if (jQuery(this).hasClass('open')) {
                jQuery(this).parent().find('div:first').slideUp('fast');
                jQuery(this).removeClass('open');
                jQuery(this).html('<img src="http://www.example.com/wp-content/plugins/wp-knowledgebase/template/images/kbe_icon-plus.png/template/images/kbe_icon-plus.png" />');
            } else {
                jQuery(this).parent().find('div:first').slideDown('fast');
                jQuery(this).html('<img src="http://www.example.com/wp-content/plugins/wp-knowledgebase/template/images/kbe_icon-plus.png/template/images/kbe_icon-minus.png" />');
                jQuery(this).addClass('open');
            }
        });

Fix:

After some additional digging, inside of wp-knowledgebase/wp-knowledgebase.php, line 457 and line 460 should be:

jQuery(this).html('<img src="<?php echo plugins_url('template/images/kbe_icon-plus.png',__FILE__) ?>" />');

and

jQuery(this).html('<img src="<?php echo plugins_url('template/images/kbe_icon-minus.png',__FILE__) ?>" />');

respectively.

And to account for the the hard coded plus background image:

.kbe_category span.switch img {
  content: none;
}

or remove the content line altogether.

https://wordpress.org/plugins/wp-knowledgebase/