bplcountry_mom bplcountry_pop have no observations (Argentina 2010)

I have downloaded the country of birth of mother and father for Argentina (2010) but when I run a crosstab, I get “no observations”

The reason for this is the “Attach Characteristics” tool relies on the use of the family interrelationship variables MOMLOC, POPLOC, and SPLOC. These variables are not available in the 2010 Argentina sample. Without these family interrelationship variables, the mother’s and father’s birthplace is not able to be linked.