It is stated in the UG that you have to use the index of the persons list to mark attendance so the error from trying to mark attendance in the glass group list is expected.
However the students are not grouped by class in the persons list:
it may be inconvenient for a TA with many students to scroll their person list to find the individual index for the few students in the class he is marking the attendance for.
It could be good to allow marking of attendance through the class list
However the students are not grouped by class in the persons list:
it may be inconvenient for a TA with many students to scroll their person list to find the individual index for the few students in the class he is marking the attendance for.
It could be good to allow marking of attendance through the class list