DIEF Error While uploading Sales Order


While importing Sales Order using Date Import Export Framework.

Sales Order Header is imported Successfully.

Sales Order Line gets inserted into Staging but doesn’t get copied to target entity.

And when I check the Error log

A value is missing. Enter a value in the Item model group field in the Released product details form for product 1 to be able to proceed .

I checked with the setups of the released products.All the setups are OK still the above error.

Can anybody let me know on the same.