HDL Issue:AssignmentSDO is required & You must provide a valid reference to the parent record

I tried to create new worker with HDL Data Loader.

But it is appeared 2 of errors like the following.

Message:You must provide a valid reference to the parent record. Ensure that the parent record is supplied in the same file, or has already been created.

MERGE|Assignment|HIRE|2001/01/01|4712/12/31|2001/01/01|BE_RES_306011_400|EBE_RES_306011_400|1|Y|E|ACTIVE_PROCESS|XX_BE_BU|E|XX_BE_LE|Y|TEBE_RES_306011_400||BE_RES_306011_400|PrimaryAssignment||000000_全社|||Employee|01.99.99.99.306011.999999.400.99.99.99

AssignmentSDO is required' and 'must enter valid assignment attribute

What is the cause do you know?

Please give me any ideas.

Thanks,

Mayuko