I'm using an external tool (launchpad) for assignments. I have set the due date, dates of availability, and published the assignment. But some of my students are receiving a message saying "The assignment is part of a unpublished module and is not available yet" while other students are not. This is evidenced by the points they received in the grade book after completion of the assignment. I also get this message while in student view. How do I resolve this issue?