Error: Edit Listing

When I click on the site to edit a listing, it gives the following error:

Warning: Cannot modify header information - headers already sent by (output started at /var/www/vhosts/directory.indie-film.tv/httpdocs/wp-includes/class.wp-scripts.php:120) in /var/www/vhosts/directory.indie-film.tv/httpdocs/wp-includes/pluggable.php on line 866