generic data source - delta not working

Hi All,

I have created one custom table and created the records for generic extraction using function module.

I could able to fetch the records in RSA3 using Full update Mode.

Once it is checked, i have created one more record in a table and then i tried to extract using Delta update mode. But it is giving error "error occured during extration". It is neither showing in RSA7.

Note: I have not replicated this data source in BW yet.

Regards,

Jo