MnglAppController.php contains hardcoded http:// call for jquery-ui google api

Because you have 2 hardcoded http:// calls in MnglAppController.php

Line 195:

if(MnglUtils::is_version_at_least( '3.0-beta2' ))
      wp_enqueue_style( 'jquery-ui-all', 'http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.2/themes/smoothness/jquery-ui.css' );

Line 205:

if(MnglUtils::is_version_at_least( '3.0-beta2' ))
    {
      wp_enqueue_script( 'jquery-ui', 'http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.2/jquery-ui.min.js', array('jquery') );

If a site is forced to SSL and your plugin is used, it affects other plugins , e.g. wpForo, so that in this plugin functions aren’t working any longer.

https://ww.wp.xz.cn/plugins/mingle/