Tag feed plug in error

I have uploaded the Tag feed Plug-in into my database. And I have installed the post indexer before this. but now when I want to add a new post, there is an error saying that " Fatal error: Call to undefined function get_blog_status() in /home/content/41/10195441/html/wp-content/plugins/post-indexer/post-indexer.php on line 225"

what should I do ?
Thanks