Reference field WA_ZEXIM-ZLGWPS unknown in form.

Hai Experts

In smart form i am getting following error

Actually i have created Y table structure in SE 11 data i am passing and importing in Smartform

WA_ZEXIM-ZLGWPS is a qunitity field i have given reference to MSEG and MEINS

ZLGWPS	ZGWPS	QUAN	MSEG	MEINS	Gross Weight Per Shipper

I am getting following erroe please help me to resolve.

Reference field WA_ZEXIM-ZLGWPS unknown in form.

Message no. SSFCOMPOSER601

Regards

Jagadish