php Notice error on plugin settings page after install

Notice: Undefined index: ss_easy_tynt_submit_hidden in /var/www/vhosts/u2314686.plsk.regruhosting.ru/imgf_ru/wp-content/plugins/easy-tynt/easy-tynt.php on line 63

I got this error after install plugin when i opened plugin’s setittings page

http://wordpress.org/plugins/easy-tynt/