Woocommerce refund and exchange plugin sending empty email

When the client request a refund of the order, woocommerce RMA plugin is sending an empty refund email to my client/users. No subject, no content.

Additional problem is that the mail configuration(Woocommerce->RAE Setting->Mail Configuration) redirects to 404 page in client page and not in admin panel page.

P.s: I’m using outlook for my emails.

Empty Email