If you change total units, or monthly units, you might receive a validation error saying 'total units must equal the sum of the individual units'. This is caused by your monthly units not matching the total units.
1. Pull your drop-down menu to Flighting, scroll to the right to see the monthly units.
2. You can either delete the monthly units, or manually change the monthly units so combined they match total units.
*TIP- When you change units, you can start with monthly units update, then use the drop down in the total Units column to recalculate.