[Plugin: MailChimp List Subscribe Form] warning message

Hey Julie!

Which version of the plugin are you currently using?

Right on!

We actually just pushed out a new version of the plugin which corrects this issue. But the root cause of this error has to do with groups in your list, or the lack thereof. My man MC_Van has a pretty detailed walkthrough of how to correct that issue in 1.2.5, here:

http://ww.wp.xz.cn/support/topic/plugin-mailchimp-list-subscribe-form-php-invalid-argument-error?replies=7

However, if the plugin is updated to 1.2.6, that error goes away for you, automatically. 🙂

If we can help with anything else, let us know!

Cheers