header error

Hi, the website uses this plugin and is running WordPress 5. Whenever I want to do a search, i get a blank page with an error on it:
Warning: Cannot modify header information – headers already sent by (output started at /data/sites/web/revabe/www/wp-content/plugins/easy-image-display/sb-easy-image-display.php:121) in /data/sites/web/revabe/www/wp-includes/pluggable.php on line 1223

Is there a solution for this?

Kind regards,
Julie

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