Error when trying to create 'new' Enhanced Landing Page

Hi All! When I am on a Campaign, I click on the Landing Pages related list, then click "New". When I try to create a new landing page, I get the error message "Hmm, that didn't work. The associated campaign needs a business unit".   I have business units set up and connected campaigns, I think (I'm not well-versed with this side of SF). I created a test campaign but found that the business unit field is not populated at all. Any ideas on what the problem could be? Thanks!