If you have graded an assignment but chosen to not release grades and feedback, students will not be able to view the information until you use the Release Grades option in Assignments.
Select the Assignments tool from the Tool Menu of your site.
Click the Grade option associated with an assignment.
Grades that have been released will display a value of Returned in the Status column and will display a checkmark in the Released column.
Note: Release Grades will not release grading and feedback to students that have not yet received any grading and feedback.