System.Globalization.CultureInfo currentCulture = System.Threading.Thread.CurrentThread.CurrentCulture;
            System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-EN");
            PdfFormatProvider provider = new PdfFormatProvider();
            RadFixedDocument document;
            using (Stream stream = File.OpenRead("popup_dedetizacao_ok.pdf"))
            {
                document = provider.Import(stream);
            }
            System.Threading.Thread.CurrentThread.CurrentCulture = currentCulture;
        

            System.Globalization.CultureInfo currentCulture = System.Threading.Thread.CurrentThread.CurrentCulture;
            System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-EN");
            PdfFormatProvider provider = new PdfFormatProvider();
            RadFixedDocument document;
            using (Stream stream = File.OpenRead("popup_dedetizacao_ok.pdf"))
            {
                document = provider.Import(stream);
            }
            System.Threading.Thread.CurrentThread.CurrentCulture = currentCulture;

            RadForm form = new RadForm();
            RadPdfViewer radPdfViewer1 = new RadPdfViewer();
            form.Controls.Add(radPdfViewer1);
            radPdfViewer1.LoadElementTree();
            radPdfViewer1.Dock = System.Windows.Forms.DockStyle.Fill;
            radPdfViewer1.Document = document;
             
            form.ShowDialog();

        private  void MergeDifferentDocumentsPagesWithFixed()
        {
            string[] documentsToMerge =
            {
                "14301-STOCK_Proforma.pdf",
                "14302-STOCK_Proforma.pdf",
                "14303-STOCK_Proforma.pdf",
                "14304-STOCK_Proforma.pdf",
                "14305-STOCK_Proforma.pdf",
                "14330-STOCK_Proforma.pdf"
            };
            RadFixedDocument doc = new RadFixedDocument();
            PdfFormatProvider provider = new PdfFormatProvider();
            foreach (string current_item in documentsToMerge)
            {
                string path = @"..\..\Samples\" + current_item;
                RadFixedDocument docToMerge;
                if (!File.Exists(path))
                {
                    continue;
                }
                using (Stream stream = File.OpenRead(path))
                {
                    docToMerge = provider.Import(stream);
                }
                doc.Merge(docToMerge);
            }


            string outputFilePath = @"..\..\mergedFixed.pdf";
            File.Delete(outputFilePath);

            using (Stream output = File.OpenWrite(outputFilePath))
            {
                provider.Export(doc, output);
            }
            Process.Start(new ProcessStartInfo() { FileName = outputFilePath, UseShellExecute = true });


        }

   private void MergeDifferentDocumentsPages(string resultFileName)
   {
       string[] documentsToMerge =
       {
           "14301-STOCK_Proforma.pdf",
           "14302-STOCK_Proforma.pdf",
           "14303-STOCK_Proforma.pdf",
           "14304-STOCK_Proforma.pdf",
           "14305-STOCK_Proforma.pdf",
           "14330-STOCK_Proforma.pdf"
       };

       File.Delete(resultFileName);
       using (PdfStreamWriter fileWriter = new PdfStreamWriter(File.OpenWrite(resultFileName)))
       {
           foreach (string documentName in documentsToMerge)
           {
               string path = @"..\..\Samples\" + documentName;
               using (PdfFileSource fileToMerge = new PdfFileSource(File.OpenRead(path)))
               {
                   foreach (PdfPageSource pageToMerge in fileToMerge.Pages)
                   {
                       fileWriter.WritePage(pageToMerge);
                   }
               }
           }
       }


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

PdfFormatProvider provider = new PdfFormatProvider();
provider.ImportSettings.DocumentUnhandledException += this.ImportSettings_DocumentUnhandledException;

private void ImportSettings_DocumentUnhandledException(object sender, DocumentUnhandledExceptionEventArgs e)
{
    if (e.Exception is InvalidGraphicOperandsCountException)
    {
        e.Handled = true;
    }
}

This exception was originally thrown at this call stack:
    Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.DocumentStructure.DocumentCatalog.CopyEmbeddedFilesTo(Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Import.Parser.PostScriptReader, Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Import.IRadFixedDocumentImportContext) in DocumentCatalog.cs

   at Telerik.Windows.Documents.Core.Fonts.Type1.Type1Format.Type1FontSource.GetFontFamily()