createRowData in PBCS groovy throws - An error while processing page

I am attempting to use Groovy to create a RowData object as part of an data import process. However, I am encountering an error message that states "An error occurred while processing this page." I am using following two methods from the documentation:

public RowData createRowData(Tuple rowMembersTuple,
                             java.util.Collection<Member> columnMembers,
                             java.util.Map<java.lang.String,java.lang.String> columnMemberNamesToValues)
public RowData createRowData(Tuple rowMembersTuple,
                             java.util.Map<java.lang.String,java.lang.String> columnMemberNamesToValues)

Version (include the version you are using, if applicable): 23.09.68

Here is the relevant code snippet:

Cube cube = operation.application.getCube("OEP_FS")
Tuple row = ['Entity': 'US1101', 'Years': 'FY23', 'Period': 'May', 'Version': 'Final', 'Scenario': 'OEP_Actual', 'Account': 'ACC55555', 'CustomDim1': 'cusdim1mbr', 'CustomDim2': 'cusdim2mbr', 'PlanElement': 'PE_ERP', 'Currency':'USD'] as Tuple

def colMbrNameToValuesMap = ['code1': 100, 'code2': 200, 'code3': 300, 'code4': 400] as Map<String,String>

Dimension code_dim = operation.application.getDimension('Vertical')

Collection<Member> columns = ['code1', 'code2', 'code3', 'code4'].collect{ code_dim.getMember(it,cube) }

Member mbr = vertical_dim.getMember('code1',cube)

RowData rowData = createRowData(row, columns, colMbrNameToValuesMap)