Releasing grades and feedback generates an email to students to alert them. Ensure you have finished your all marking and feedback before you release the grades.
This makes the grades and feedback visible and generates an email to students to alert them to their released grade and feedback.
When an assignment is set up with anonymous marking, you must unhide the grade item and reveal student identities in order to release grades and feedback.
If you have released the grades and students still can't view their grades, check the following:
Individual grade items can be hidden in the Grader Report.