ax 2009 batch job getting Error executing code: TextIo object not initialized.

HI,

I have a created batch job today, while running it manually it works fine but while executing it by batch i am getting following error:

 Error executing code: TextIo object not initialized.

(S)\Classes\TextIo\writeExp

(S)\Classes\productMaster\run - line 48

(S)\Classes\BatchRun\runJobStatic - line 63

the code which i have is

public void run()

{

    int a;

    ;

   /* dlg  = new dialog("PRODUCT MASTER");

    dlgg = dlg.addGroup("DISTRIBUTOR ID");

    dlgf = dlg.addField(typeid(Name),"DISTRIBUTOR ID");

    dlgf.value("10033");    */

    ltCurrentDate = today();

    //dlgf = dlg.addField(TypeID(TransDate),"To Date");

//     if(dlg.run())

//    {

        //FileName = @"D:\\SOLOMAN\\SCBDTL.TXT" ;

        //LT rr commented to have different path

        //FileName = @"C:\\Principals\\Consumer\\ProdMaster.csv";

        /* LT rr new added */

        ltDist = '10033';

        ltDate = date2str(ltCurrentDate,321,

                                        DateDay::Digits2,DateSeparator::None,

                                        DateMonth::Digits2,DateSeparator::None,

                                        DateYear::Digits4);

        ltFileName = strfmt("%1 _PRODUCTMASTER_ %2" ,ltDist,ltDate);

        FileName = strfmt(@"U:\\ADMMI\\%1.tab",ltFileName);

       // FileName = strfmt( @"C:\\Principals\\Consumer\\%1.tab",ltFileName);

        permission = new FileIOPermission(filename, #IO_Write);

        permission.assert();

        //FileName = @"C:\SCBDTL.TXT" ;

        file = new TextIO(FileName, #io_write);

        //LT rr commented

        //file.outFieldDelimiter(';');// for semicolon seperator

        //LT rr

        ltHeaders = ["Distributer_ID   SKU_ID            GSK_Code         GSK_Description                    UOM" ];

        file.writeExp(ltHeaders);

        file.outFieldDelimiter('   ');

        if (!file || file.status() != IO_Status::Ok)

        {

            throw error("File cannot be opened.");

        }

        while select itemTable

        Where itemTable.ADMInventAgencyId == 'A007'

        {

            select custVendExternalItem where custVendExternalItem.ItemId == itemTable.ItemId

                                        && custVendExternalItem.ModuleType == ModuleInventPurchSalesVendCustGroup::Vend;

            sno++;

            DistID  = '10033';

            SKUID   = StrLRTrim(itemtable.ItemId);

            GSKCODE = StrLRTrim(custVendExternalItem.ExternalItemId);

            SKUDESC = StrLRTrim(itemtable.ItemName);

            UOM     =  StrLRTrim(itemtable.inventUnitId());

            line = [DistID, SKUID, GSKCODE, SKUDESC, UOM];

            file.writeExp(line);

     }

        sno = 0;

 // }

}

i have highlighted the code which is causing error:

Kindly guide me further to fix it!!!!