Error at post indexer

There is something not right at the post indexer. When i open the page “new post” at http://members.socialnetworkersunited.com/wp-admin/post-new.php i get the next error:

Fatal error: Call to undefined function get_blog_status() in /home/socialnetw/domains/members.socialnetworkersunited.com/public_html/wp-content/plugins/post-indexer/post-indexer.php on line 225