Fatal error: Uncaught Error: Call to undefined function add_action() in /home/artemi19/public_html/test/wp-content/plugins/jetpack/modules/sso.php:23 Stack trace: #0 /home/artemi19/public_html/test/wp-content/plugins/jetpack/modules/sso.php(59): Jetpack_SSO->__construct() #1 /home/artemi19/public_html/test/wp-content/plugins/jetpack/modules/sso.php(1071): Jetpack_SSO::get_instance() #2 {main} thrown in /home/artemi19/public_html/test/wp-content/plugins/jetpack/modules/sso.php on line 23