A student cannot take a quiz before the deadline for whatever reason. The teacher accepts the student excuse, and allows the student to take the quiz even though the deadline has passed.

The teacher has to extend the time in the quiz by adding days.

The student still cannot take the quiz because the teacher marked the assignment as Missing in the grade book (so the parent and student would know there is a missing assignment) and marked the grade as a Zero (otherwise the missing assignment would not be used in calculation of the cumulative quarter grade.

The solution from support currently is to delete the zero grade and unmark the assignment as missing. Then the student can take the assessment within the LMS.

That defeats the purpose of marking as missing and giving a grade of zero.