Problem returning error messages in importer step of custom integrator

Hi,

I have a problem returning error messages in a custom integrator.

Structure is as follows:

Interface Columns of table H3G_AR_MANUAL_TRX_TB:

INVOICE_NUMBER, LINE_NUMBER, STATUS, MESSAGES

Group Definition:

INVOICE_NUMBER

Importer: Document Row Interface Attribute Mapping(Identifies each line):

INVOICE_NUMBER, LINE_NUMBER

API Call:

With Source: Import, Value: H3G_AR_MANUAL_TRX_TBL.INVOICE_NUMBER

Error Row Definition:

SELECT t1.* FROM H3G_AR_MANUAL_TRX_TBL t1 WHERE t1.status = 'E' AND t1.INVOICE_NUMBER = $PARAM$.P_INVOICE_NUMBER

With P_INVOICE_NUMBER as Source: Import, Value: H3G_AR_MANUAL_TRX_TBL.INVOICE_NUMBER