Verify that email recipients have user accounts
If you want student contacts to be able to receive notifications and view published reports, you have to have the Family portal a view in Aspen where authorized parents and students can access student data, including attendance, assignments, conduct incidents, and grades up and running. Part of this setup involves creating user accounts. Without a user account the login ID and password needed to access Aspen, a person cannot log on to Aspen and therefore can't access a published report.
See Setting Up the Family and Student Portals for more information.