The following issue is currently scheduled to be fixed and released in Sprint 52.
Issue: There is currently an issue with the Deleted Classes tool where you cannot remove the students from a class in bulk if the class has a future start date. The issue specifically revolves around the Drop date field not allowing you to set a future date for when the class starts but also not allowing you to set the current date or a past date because the class hasn't started yet. You can expect to experience the following errors if you try to edit the drop date of a future class in the Delete Classes tool:
1. Error Message Displayed when you enter the Date after the course ends :
2: Error Message Displayed when you enter the Date before the course ends :
Manual Workaround
A workaround for right now is to edit each individual student's timetable directly through the student record. You will be able to drop the class there until we get this issue fixed.