not getting correct response while using latest version

Hi there !!

In the latest version i.e., 3.9.4, when I am trying to submit the newsletter form by using javascript, I am getting a form in response.
But in the previous version it was all working fine and was getting the error or success messages in response.

So, kindly provide me the appropriate solution or patch for this problem.

Thanks in advance !!

https://wordpress.org/plugins/newsletter/