The file
mgc_cb_evo/plugins/fetch_userinfo_query.php contains an error
PHP Code:
<?
$hook_query_fields .= ",mgcugp.mgc_cb_evo_default_color,mgcugp.mgc_cb_evo_chanid";
$hook_query_joins .= " LEFT JOIN " . TABLE_PREFIX . "usergroup AS mgcugp ON (user.usergroupid=mgcugp.usergroupid) ";
?>
You should add 'php' after the opening tag (<?php). It will fix a lot of issues users are having related to the permanent 'loading...' issues and is coding wise best practice.