void ExportFile(VouchersClient voucher, ZipOutputStream zipOutputStream)
        {
            byte[] attachment = voucher.Buffer;
            voucher._Data       = null;
            voucher._LoadedData = null;
            if (attachment == null)
            {
                if (voucher._Url != null)
                {
                    try
                    {
                        if (voucher.IsWebUrl)
                        {
#if !SILVERLIGHT
                            attachment = new WebClient().DownloadData(voucher._Url);
                            var ext = System.IO.Path.GetExtension(voucher._Url);
                            if (ext != null)
                            {
                                voucher._Fileextension = DocumentConvert.GetDocumentType(DocumentConvert.GetExtension(ext));
                            }
#endif
                        }
                        else
                        {
#if SILVERLIGHT
                            attachment = UtilFunctions.LoadFile(voucher._Url);
#else
                            attachment = UtilFunctions.LoadFile(voucher._Url).GetAwaiter().GetResult();
#endif
                        }
                        if (attachment == null)
                        {
                            return;
                        }
                    }
                    catch
                    {
                        return;
                    }
                }
                else
                {
                    return;
                }
            }
            // Write the data to the ZIP file
            var sb = StringBuilderReuse.Create(voucher._Text).Replace('/', '-').Replace('\\', '-');
            sb.Append('_').Append(voucher.RowId).Append('.').Append(Enum.GetName(typeof(FileextensionsTypes), IdObject.get((byte)voucher._Fileextension)));
            var name = sb.ToStringAndRelease();
            zipOutputStream.PutNextEntry(new ZipEntry(name));
            zipOutputStream.Write(attachment, 0, attachment.Length);
            WriteLogLine(string.Format(Uniconta.ClientTools.Localization.lookup("ExportingFile"), name));
        }