This error occurs because there are duplicate records within the File based on the Operational Key.
The Enrollment file submitted contains two records that CALPADS interprets as the same record. Both records have the same SSID, School of Attendance, and Enrollment Start Date. These are the fields that CALPADS uses to uniquely identify a record in the ODS. Therefore, there cannot be two records with the same unique identifiers.
The newly developed Enrollment Update process was redesigned in Aeries to prevent duplicate records form being extracted within a file where the operational keys might be duplicated.
One reason that this could happen is if the file record was generated using the old method or the Legacy extract method.
Verify that the extract was created using the new method described in the following document.
Use the new method and submit each file one at a time starting with 001, 002, 003, etc. as described in the documentation.