CoursePress User with correct permissions can't access course categories in admin

We have found that a subscriber user who has been granted instructor privileges can't access the Course Categories submenu item in the admin panel, despite the fact that they have the coursepress_courses_cap capability required to access it. Here are the steps to reproduce:

-- Create a new subscriber user
-- Grant the user instructor privileges
-- Log in as the user and try to access Course Categories

When we've done this, we get the Cheatin' uh? error message.