Many of our sites are on SSL (https://), and therefore, apparently, because you use the following, we get many mixed content pop-ups in Internet Explorer (used by our users! not us ;) ) for your plugins.
WP_CONTENT_DIR // no trailing slash, full paths only WP_CONTENT_URL // full url WP_PLUGIN_DIR // full path, no trailing slash WP_PLUGIN_URL // full url, no trailing slash
define( "CMS_TPV_URL", plugins_url() . '/cms-tree-page-view/');
Already referenced the issue here: