Share This Problem with comments

I try to use the Share This Plugin but i have a little problem

For example in this page:
https://www.ifd.com.br/blog/2007/04/30/vaga-assit-de-direcao-de-cena

COMPARTILHAR MATERIA | DICA (is SHARE THIS)

I put on single.php the <?php akst_share_link(); ?> where I decided the SHARE THIS will appear – all is ok, but I see the popup not appear and in the footer of the single.php I put <?php akst_share_form(); ?> exactly the readme is explain https://alexking.org/projects/wordpress/readme?project=share-this

…allll is OK BUTTTTTTTTTTTT when someone try to comment in the post appear an ERROR (the error is : THE WORDPRESS NOT SURE THAT YOUR EMAIL IS VALID, PLEASE TRY AGAIN)

When I take of the code <?php akst_share_form(); ?> on the single.php the comment works, BUTTTTTTTTTTTTTTTTTT the popup of share this doesn’t appear ??

How can I resolve this?

and sorry about my English I hope someone can understand ??