To resolve this issue, follow these steps:

1. Check for duplicate student accounts:
   Make sure that you don't have multiple student accounts with the same email address.


2. Check if the student is in the right class:
   Confirm if the student is part of the class where you are assigning the work.


3. Check the assignment setting:
   Ensure that the assignment is set up to be visble to specific students.


4. Check the class roster:
   Verify whether the student is in the class roster, and if not add them.


5. Check student permission:
   Make sure they have permission to view the assignment.