Should you see the exception "Error reported from RE on saving the record from the area map "Constituent Mapping". The reported error was: Required Field Missing:  Bank," you should check to see if you have selected the payment method of "Direct Debit."  Raiser's Edge requires a Bank mapping to be linked to this payment method.  Importacular cannot workaround that requirement, so this can only be resolved by changing the payment method to something else (such as Cash or Other) or using the paid destination for Banks and Financial Relationships.