Once you have a satisfactory master schedule, you can begin fine-tuning student schedules by running a load.
Do not load students into your master schedule until you are satisfied with it. Loading will not have any impact on the structure of the schedule, just on the placement of students within it. Also, do not make manual adjustments to student schedules and then reload students; the system will overwrite all of the changes you made.
Note: It is recommended that you run the first load before you define any load constraints.