Error when clients attempting to log in

When clients attempt to login errors being received:

Warning: method_exists() expects exactly 2 parameters, 1 given in /home/customer/www/listinguniversity.com/public_html/wp-content/plugins/pilotpress/pilotpress.php on line 1396

Warning: Cannot modify header information – headers already sent by (output started at /home/customer/www/listinguniversity.com/public_html/wp-content/plugins/pilotpress/pilotpress.php:1396) in /home/customer/www/listinguniversity.com/public_html/wp-includes/pluggable.php on line 1340

The page I need help with: [log in to see the link]