I have been using mailchimp as my website sign up. Suddenly it cannot be used. I have used naked form to input into the optin portion, when sign up, mailchimp gives an error that email is not entered.
Please watch this video: https://imsuccesscenter.com/customercare/index.php?/Knowledgebase/Article/View/79/23/profit-builder---how-to-check-for-optin-form-field-errors and make sure that you have selected the email field properly (and name field if you have this), as this is why you're seeing this issue. Once you have properly selected the email field, save the page and try again.