When users signup to my website, I receive an error stating the following:
there has been an error with a new subscriber to your newsletter! Check the error and send a message to the user if signup to the newsletter has been unsuccessful. Unable to load listSubscribe()! UserID: Name: Email: Code: -90 Msg: You must specify a email_address value for the listSubscribe method
I have not modified the code in any way, and know my API key is correct.