title: .xslm to .xslx using workbook.SaveAs() in Interop.Excel, executes with no issue but not saving the file
body: <p>Interop.Excel version 12</p>
  
  <p>Office Excel 2007</p>
  
  <p>I have worked on code to open .xslm file and then converting (saving) it as .xslx. Between this, I do need to do some processing as well but it doesn't matter. Following is the code:</p>
  
  <pre><code>namespace Exceltest
  {
      class Program
      {
          static void Main(string[] args)
          {
  
              Application oXL = null;
              oXL = new Application();
  
              oXL.Visible = false;
              oXL.DisplayAlerts = false;
  
              try
              {
                  Workbook book = oXL.Workbooks.Open("E:\\CorrectPF1.xlsm", 0, true, 5, "access123", "", true,
                                                     XlPlatform.xlWindows, "\t", false, false, 0, true, null, XlCorruptLoad.xlNormalLoad);
  
                  Worksheet worksheet = (Worksheet)book.Sheets["Resource allocation"];
                  worksheet.Activate();
  
                  oXL.Visible = false;
                  oXL.DisplayAlerts = false;
  
                  book.SaveAs("E:\\PF1.xlsx", XlFileFormat.xlOpenXMLWorkbook,
                                              "", Type.Missing, Type.Missing, Type.Missing, XlSaveAsAccessMode.xlNoChange,
                                                  XlSaveConflictResolution.xlLocalSessionChanges, Type.Missing, Type.Missing,
                                                  Type.Missing, false);
              }
              catch (Exception  ex)
              {
               //Handling exception here
              }
  
          }
      }
  }
  </code></pre>
  
  <p>This code executes with no issue (without any exception) but No file is saved with .xslx extension. I found it is working for some set of files but not others. Say, it is not working for file named PF1.xslm. I am able to open PF1.xslm in Office Excel and save it as .xslx. So, the same suppose to work programmatically as well.</p>