Error message in SmartForm

I am trying to test a SmartForm and I get the following error:

Exception FORMATTING_ERROR

Message ID: SSFCOMPOSER Message number: 601

Message:

Reference field WA_ITEM_DATA-BMNG2 unknown in form.

I am testing using the test environment (not a print program). I am using wa_item_data-bmng2 in the form inside a table. I added the field by dragging it from the field list so I know that there are not any typos. Does anybody have any idea what could be wrong?

Regards,

Davis