Loading Mandatory Objects of Worker File Using HDL

Summary

I am trying to load the basic hdl file using the mandatory object.I want to load it using the user keys .

Content

I am trying to load the basic hdl file using the mandatory object.I want to load it using the user keys . I am getting the assignment SDO Error and 

A parent for this record was not found. Use any of the four supported key-resolution systems to supply a valid parent reference.

 when trying to import the file.Can anyone let me know what is the mistake am I commiting here 

METADATA|Worker|EffectiveStartDate|EffectiveEndDate|StartDate|PersonNumber|ActionCode