Results. The value "DataSourceName" is not found in the map.

Error: Results. The value "DataSourceName" is not found in the map.

Usually happens when adding Name from DirPerson (DirPartyTable) data source joined to HcmWorker_Orderer data source on PurchPurchaseOrderHeaderV2Entity data entity or HcmWorker_OrderResponsible / HcmWorker_OrderTaker data sources on SalesOrderHeaderV3Entity data entity.

Remove the new data source and replace the column with computer one:

/// <summary>
/// Extension Class for PurchPurchaseOrderHeaderV2Entity data entity.
/// </summary>
[ExtensionOf(dataentityviewstr(PurchPurchaseOrderHeaderV2Entity))]
final class VKPurchPurchaseOrderHeaderV2Entity_Extension
{
    public static str getOrdererName()
    {
        DictView    purchaseOrderEntity = new DictView(tableNum(PurchPurchaseOrderHeaderV2Entity));
        str         orderEntityDS       = dataEntityDataSourceStr(PurchPurchaseOrderHeaderV2Entity, HcmWorker_Orderer);

        str sqlQuery = strFmt(@"select %1 from %2 where %3=%4",
                                fieldStr(DirPerson, Name),
                                tableStr(DirPartyTable),
                                fieldStr(DirPartyTable, RecId),
                                purchaseOrderEntity.computedColumnString(orderEntityDS, fieldStr(HcmWorker, Person))
            );

        return sqlQuery;
    }
}

Data entity field:

        <AxDataEntityViewField xmlns=""
            i:type="AxDataEntityViewUnmappedFieldString">
            <Name>VKOrdererName</Name>
            <AllowEdit>No</AllowEdit>
            <AllowEditOnCreate>No</AllowEditOnCreate>
            <ComputedFieldMethod>VKPurchPurchaseOrderHeaderV2Entity_Extension::getOrdererName</ComputedFieldMethod>
            <ExtendedDataType>DirPartyName</ExtendedDataType>
        </AxDataEntityViewField>