Fatal error: Uncaught Error: Call to undefined function add_action() in /usr/www/users/dalc/wp-content/plugins/jetpack/modules/related-posts.php:42 Stack trace: #0 /usr/www/users/dalc/wp-content/plugins/jetpack/modules/related-posts.php(30): Jetpack_RelatedPosts_Module->__construct() #1 /usr/www/users/dalc/wp-content/plugins/jetpack/modules/related-posts.php(66): Jetpack_RelatedPosts_Module::instance() #2 {main} thrown in /usr/www/users/dalc/wp-content/plugins/jetpack/modules/related-posts.php on line 42