Created Unassigned: System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown [14125]

Getting Exception while export:

__fieldValue:__ 02048906_00000
__Code:__ crow.CreateCell(cellindex).SetCellValue(Convert.ToString(fieldValue));

__Exception:__
at System.Text.StringBuilder..ctor(String value, Int32 startIndex, Int32 length, Int32 capacity)
at NPOI.SS.Util.CellReference.FormatAsString()
at NPOI.XSSF.UserModel.XSSFCell.SetCellNum(Int32 num)
at NPOI.XSSF.UserModel.XSSFRow.CreateCell(Int32 columnIndex, CellType type)
at NPOI.XSSF.UserModel.XSSFRow.CreateCell(Int32 columnIndex)

Please Help...