When I test an email campaign, the button that links to a Package Landing Page does not work.
This may happen because your email is not associated with an account on the campaign. The button will only take a real user, associated with a real account, to the embedded URL. Your customers will be able to click the call to action button and see the corresponding page because their email is associated with a real business account in the selected market. You will not be able to test it under most circumstances, because you are not the customer.