Custom fields removal, on 3rd party services. (MMERGE must be provided error)


Some 3rd party services such as MailChimp, allow adding custom fields to their accounts, aside from Name and Email Address. If these custom fields are enabled, the potential subscriber needs to provide that information, and sometimes this results in the following error: 

"ERROR: {"error":"MMERGE3 must be provided - Please enter a value","code":250}" 

We wouldn't want you to miss the chance of getting new subscribers to your newsletter, so to solve this, please check if you have any custom fields in your 3rd party service list, that are marked as “Required”. 

If you have the default MailChimp settings, then you won’t have to change anything. However, if you have added any custom fields to your list, you need to uncheck any “required” fields you have on your account. Otherwise, they will not post to MailChimp from your form.

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