I have upgraded wordpress version to the latest along with plugins. I have encountered this error message on my blog as well as while trying to login into the admin area of the blog:
Fatal error: Call to undefined function: str_split() in /home/…/htdocs/wp-content/plugins/pods/init.php on line 27
– str_split is a PHP 5 function. It seems that your site/blog is running on PHP4 version. Hence, upgrade your domain/blog PHP version to PHP5 with the help of your hosting service provider. Once you upgrade it, your problem should be resolved positively.