1. Enter as instructor
2. Create an assessment
3. Create one question
4. Click on settings
5. Set the available date and the retract date set in the past, leave the due date blank.
6. Publish the assessment
7. Enter as student
8. Take the assessment
9. You´ll see a message ("Assessment is no longer available")
In my opinion, an assessment with the retract date over must be inactive and not visible for the student.
Furthermore, why SAMIGO let you save the settings with no due date and retract date with the option "Yes until"?
I think that´s confusing because it lets you publish an assessment wich is active but no one can take.