MailChimp plug-in troubles

Hi all.

We have a MailChimp widget on our home page for people to subscribe to our newsletter. However, when I try to sign up, I get this error message:

General/standard error message: “Oops. Something went wrong. Please try again later.”
Additional error message: “Admin notice: FNAME must be provided – Please enter a value”

In my dashboard under the Form mark-up field, here are my error messages:

Your form is missing the following (required) form fields:

– A ‘FNAME’ field
– A ‘LNAME’ field

Can anyone help me with this? What do I need to do so that people can enter their email and sign up?

Laura