In some cases, a scholar may receive a "No Preview Available" message when they click on the link to a quiz from the To Do list or the Dashboard's List view.
Click the link with the title of the quiz at the top of the submission details page. Or, navigate to the quiz via course Modules. These links will always open the quiz itself, rather than the graded submission.
Instructure investigated this issue with us and determined that this is a consequence of the assignment being already graded.
The Canvas feature "New Quizzes" is an external tool. If a grade is ever assigned, the assignment is considered "graded," even if that grade is cleared. This is most likely to occur in the case an assignment is auto-graded due to being late, or it can also occur if the teacher manually grades the assignment, including setting a point value of 0 points.
Once a "New Quizzes" assignment has been graded, links to the assignment go directly to the submission page, rather than to the quiz.