Hello there, @erin_garvey ...

Sorry to see that your question has been sitting out here unanswered since the beginning of August.  You said that you made your own links to areas of your course.  If you made your own link to your "Modules" index page, for example, and you hid that "Modules" course navigation button from your students, that is most likely why you are seeing that error message.  The "Modules" page would need to be visible in order for your students to access that page.  But, if you are linking to individual content pages, assignments, discussion topics, etc., you should still be able to link to those items even if the "Pages", "Assignments", and "Discussions" course navigation buttons are hidden from your students.  Does this help?  Please let Community members know if there is anything else we can do to assist...thanks!