OK – just made a support ticket from your link.
And below the notice is:
Warning: Cannot modify header information – headers already sent by (output started at /var/www/vhosts/pumpmakers.com/subdomains/beta2/wp-includes/functions.php:3370) in /var/www/vhosts/pumpmakers.com/subdomains/beta2/wp-includes/class-wp-ajax-response.php on line 189
