at Telerik.Windows.Documents.Utilities.Guard.ThrowExceptionIfTrue(Boolean condition, String message)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.IndirectObject.get_Content()
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Export.PdfExportContext.BeginExportIndirectObject(IndirectObject indirectObject, Int64 offset)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.IndirectObject.Write(PdfWriter writer, IPdfExportContext context)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Export.PdfExporter.WritePendingIndirectObjects(IPdfExportContext context, PdfWriter writer)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Export.PdfExporter.WriteFontsFromContext(PdfWriter writer, IPdfExportContext context)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Export.PdfExporter.Export(IRadFixedDocumentExportContext context, Stream output)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.PdfFormatProvider.<>c__DisplayClass21_0.<ExportOverride>b__0()
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.ExceptionHandling.ExecutionHandler.TryHandleExecution[E](Action operation)
   at Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.PdfFormatProvider.ExportOverride(RadFixedDocument document, Stream output, CancellationToken cancellationToken)
   at Telerik.Windows.Documents.Common.FormatProviders.FormatProviderBase`1.Export(T document, Stream output, Nullable`1 timeout)

            string inputFilePath = "test1.doc";
            Telerik.Windows.Documents.Flow.Model.RadFlowDocument document;
            Telerik.Windows.Documents.Flow.FormatProviders.Doc.DocFormatProvider doc_provider = new Telerik.Windows.Documents.Flow.FormatProviders.Doc.DocFormatProvider();
            using (Stream input = File.OpenRead(inputFilePath))
            {
                document = doc_provider.Import(input, TimeSpan.FromSeconds(10));
            }

            Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider docx_provider = new Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider();
            string outputFilePath = "Exported.docx";
            using (Stream output = File.OpenWrite(outputFilePath))
            { 
                docx_provider.Export(document, output, TimeSpan.FromSeconds(10));
            }

            Process.Start(new ProcessStartInfo() { FileName = outputFilePath, UseShellExecute = true });

                BlockCollection footerContent = this.document.Sections.First().Footers.Default.Blocks;
                Table footerTable = footerContent.First() as Table;
                var cells = footerTable.Rows.Last().Cells.Where(x => x.EnumerateChildrenOfType<FieldCharacter>().Any());
                foreach (var cell in cells)
                {
                    cell.Blocks.AddParagraph().Inlines.AddRun();
                }

foreach (var paragraph in this.document.EnumerateChildrenOfType<Paragraph>())
{
	HeightType? heightType = paragraph.Properties.LineSpacingType.GetActualValue();
	if (heightType == HeightType.Exact || heightType == HeightType.AtLeast) 
	{
		paragraph.Properties.LineSpacingType.LocalValue = Telerik.Windows.Documents.Flow.Model.Styles.HeightType.Auto;
		paragraph.Properties.LineSpacing.LocalValue = 2;
	}
}