Fatal error: Uncaught Error: Call to undefined function add_action() in C:\xampp\htdocs\wp-content\plugins\members\addons\members-role-hierarchy\admin\class-manage-roles.php:57 Stack trace: #0 C:\xampp\htdocs\wp-content\plugins\members\addons\members-role-hierarchy\admin\class-manage-roles.php(33): MRH_Manage_Roles->setup_actions() #1 C:\xampp\htdocs\wp-content\plugins\members\addons\members-role-hierarchy\admin\class-manage-roles.php(125): MRH_Manage_Roles::get_instance() #2 {main} thrown in C:\xampp\htdocs\wp-content\plugins\members\addons\members-role-hierarchy\admin\class-manage-roles.php on line 57