When none of the permissions are given to a student, a warning message appears saying "you are not allowed to view the assignment." This message is replicated several times, according to the number of assignments the instructor has posted. Only one message should be given, and it might be rephrased to "you are not allowed to view the assignment(s)"
The student's window still lists those assignments that are open and have no submissions. When you click on one of these assignments, a VelocityServer error appears. If the student is not given 'read' permissions, should he still be able to see the assignment titles?
If the TA is given not given any permissions, it acts a little different. The TA will see the list of all open assignments (even those with submissions) and no warning shows on top (the "you are not allowed to view the assignment" message). When an assignment is clicked, then the VelocityServer error shows up.