Thank you so much! That was the issue - I had not hit the PUBLISH button yet on my modules or on my assignments. I did that just now and they all appear under student view. Thank you so much for your help!
I get this error message (i.e. "No modules have been defined for this course.") in "Student View" even when I've published the course. (The course status says it's published).
So, how do I "define a module" to make my course content available to my students?
It appears that the green published icon within every module must be activated in order for anything to show up in student view. I'm not sure if that's accurate, but that seemed to solve this problem.