What should I change if my students cannot see the quiz I created?
Turn editing on. Check to make sure the eye is open next to the quiz. If it is closed, then click it to open it. Or if you see a Restricted access message,
then click the wrench to update the quiz and scroll all of the way down to the bottom of the screen to Restrict access. Uncheck the boxes beside the dates and be sure that all items are unchecked and that drop-down menus show "none". Then save. This is a new feature of Moodle that allows instructors to set up conditional parameters.