Details on this post: https://help.swimisca.org/constant-contact-fail-subscribers-on-one-list-can-not-join-any-additional-lists/   Once a subscriber is onto one list at Constant Contact, the same subscriber can NOT join any additional lists. This occurs via the 3rd party plugins of Thrive Themes as well as Ninja Forms. That is a fatal flaw that puts our entire system of contact management with customers at jeopardy. Here is how you can test it (with Thrive Themes): Go to this page: https://help.swimisca.org/get-news-emails/ Then sign up for one list. Fine. Works. Then sign up for another list -- and you get an error message. See attached screen shot below with the little pink area showing the error. How can you fix this? Please advise. ... View more