BN531 Error: "Premium Record does not exist for Employee"

unknown

I am trying to load an enrollment file for a new 401k match plan using BN531. I get the error "Premium Record does not exist for Employee". I have seen KB1212118 that says to use Start Date instead of Enrollment Date in the csv file. It will load if I do the opposite of that (Enrollment Date instead of Start Date) but then it puts a start date in for everyone equal to the start date of the plan. Is it possible to load them with a start date that is different than the start date of the plan?

Koch Industries Talent Acquisition Transformation -20200827 1801-1.mp4

unknown

Every payperiod I use BN531 to upload deferral changes in our 403b plan. Start date is the field that is populated in the csv file. Your start date can be different that then start of the plan....but the start date cannot be before the start date of the 401k plan start date.