Mailchimp Integration Attempt leads to Error 500


Here are the steps I take to integrate Mailchimp with Unbounce:

  1. Click “Mailchimp Integration Button” on my landing page, which takes me to Mailchimp
  2. I log in to my Mailchimp account
  3. I wait and then it tells me I have an Error 500 (they don’t clarify what this is)
  4. I go back to Unbounce, which now says Unbounce and Mailchimp are connected because there’s an “Edit” button instead of a plus sign to add a new account
  5. I click the edit button. A pop-up appears that says “Mailchimp and Unbounce are talking”
  6. The pop-up stalls for the next 5 minutes.

Could anyone offer insight into a workaround or what may be going wrong?



I am using the Unbounce to MailChimp integration. I haven’t seen this message but the biggest challenge I had was getting the Unbounce form to synch with the MailChimp sign-up form. You do need to make sure that the fields in your Unbounce forms are exactly the same as the fields in your MailChimp Sign-up form for each list that you are synching too, otherwise you will get an Unbounce error message.

Make sure they match the MailChimp fields exactly - you can compare the two by navigating to List > Sign up Forms > Form Builder in Mailchimp. MailChimp told me that they need the field values to be mirror images.


When I did the integration it didn’t work as you describe. On your landing page dashboard (i.e. not in ‘edit’ mode), scroll down to ‘integrations’ and click on the ‘MailChimp’ button. You will see a pop-up box that says - Send leads to your MailChimp list
MailChimp is an email marketing and email list manager. Find out more »

Your page is successfully integrated with MailChimp!
List: The Good Exchange Leads Prospect List - you need to pick which list you want to synch to
Groups: Funder Prospect, Leads e.g. from downloads and events
Send Leads a: I’ll set up an auto-responder manually in MailChimp
Looking for lists from a different MailChimp Account?

Configure Field Mapping

You will need to choose which MailChimp list to integrate to and then map the fields between MailChimp and your Unbounce landing page. As I said above, the fields have to match exactly (including the contents of any radio buttons or check boxes)