Thank you for using our theme.
We are sorry, but we don’t guarantee compatibility with third-party plugins. Sometimes, not always, you need additionally customize theme or plugin to make them work together. Unfortunately, it’s not possible for the author to make theme compatible with all the existing plugins.
You may create MailChimp form using free version of this plugin. Read more http://xstore.helpscoutdocs.com/article/66-mailchimp-form-custom-styles (MailChimp documentation you can find here https://mc4wp.com/kb/).