I'm getting an obscure error using FreeFillableForms. The error does not appear to be on the standard table of X000-005 errors.

Issue : Business Rule X0000-005 - The XML data has failed schema validation. cvc-complex-type.2.4.b. The content of element 'WagesNotShownSch' is not complete. One of '{"http://www.irs.gov/efile":WagesNotShownAmt}' is expected.

The following information may help you determine the form at issue: Field/Xpath: /efile:Return1/efile:ReturnData1/efile:WagesNotShownSchedule1/efile:WagesNotShownSch1/efile:WagesLiteralCd1

How can I fix this?