Transformation Rule Type “Read from DataStore” Error

Hello, guys!

I've crated transformation between two DSO's with Read from DataStore rule for one Info Object which is not present in sourse DSO.

So I'm doing lookup from another DSO for that info object.

I've assigned both key fields and mapped everything as it is described here.

But during DTP execution there is error CANNOT READ FROM DATASTORE OBJECT ZXREF3O1 FOR RECORD 1

Any ideas?

Thanks in advance,

Nik.