Fatal error: Uncaught Error: Call to undefined function add_filter() in /home/adaptyo3/public_html/wp-content/plugins/QUARENTINE/user-switching/user-switching.php:50 Stack trace: #0 /home/adaptyo3/public_html/wp-content/plugins/QUARENTINE/user-switching/user-switching.php(876): user_switching->__construct() #1 /home/adaptyo3/public_html/wp-content/plugins/QUARENTINE/user-switching/user-switching.php(1089): user_switching::get_instance() #2 {main} thrown in /home/adaptyo3/public_html/wp-content/plugins/QUARENTINE/user-switching/user-switching.php on line 50