Force User Login For Free Units

I’d like to force users to sign-up and login in order to access the free units offered.

I’ve tried using Protected Content a few different ways but it causes a few issues, or doesn’t work as I’d like:

1) I tried protecting Custom Course Types > “course”. But that makes guests unable to view the course summary page (myurl.com/courses/mycourse/).

2) Tried Protecting Custom Course Types > “units” thinking maybe they’d be unable to access the units themselves, but that made the Course Structure disappear, and thus they are unable to navigate to the “Free” link. Aside from the fact they can’t navigate to the free content (and thus be asked to log in), I’d still like the course structure to show up so potential students can see an overview.

3) Finally I tried using URL Restrictions and tried to restrict access to “myurl.com/courses/mycourse/units/” which should hide that and any child pages. This didn’t seem to have any effect whatsoever. When clicking the “Free” link it would lead them to the page without signing in.

Any other ideas? Really I’m just trying to capture their email addresses so I can follow up if they don’t continue on to the paid units of the course, and thought forcing them to login would be the easiest way.

Sidenote: After installing Protected Content the “Instructors” area on the course summary page has lost/altered the CSS which applies to it. I’m using a child theme, but have done little CSS editing (aside from changing some colouring) to the default CoursePress theme.