Ax2012 R3 : Class object does not have method 'getFieldsSequence'

Hi

I m trying to export VendPackingSlipTrans records with additional fields from other table using a custom entity of the data import/export-Framework (DIXF). For That , i created VendPackingSlipTransEntity , DMFVendPackingSlipTransClass and VendPackingSlipTransTargetQuery, so for each additional field i created a generate method .

I get the following error when i try to test my export by create a new Target entities in Data import export framword>Target entities : Error executing code: DMFVendPackingSlipTransClass object does not have method ‘getFieldsSequence’.

Please help me for fix this error on AX 2012 R3