A parent for this record wasn't found. Use any of the four supported key-resolution systems to suppl

Summary

While importing a Worker.dat file via HDL i'm getting the error : A parent for this record wasn't found. Use any of the four supported key-resolution systems to supply a valid parent reference.

Content

While importing a Worker.dat file via HDL i'm getting the error :

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

Worker.dat file content :

METADATA|WorkTerms|FLEX:PER_ASG_DF|functional(PER_ASG_DF=Global Data Elements)|profession(PER_ASG_DF=Global Data Elements)|ActionCode|AssignmentNumber|EffectiveEndDate|EffectiveLatestChange|EffectiveSequence|EffectiveStartDate|PersonNumber|SourceSystemOwner|SourceSystemId