title: Excel interop - saving my newly created spreadsheet throws an exception
body: <p>I am using C# to create a spreadsheet, here is the code:</p>
  
  <pre><code>try
  {
      _excel = new Excel.Application();
      _excel.Visible = false;
      _workbook = _excel.Workbooks.Add( Type.Missing );
      _worksheet = (Excel.Worksheet)_workbook.Sheets[1];
      createColumnHeaders();
      _workbook.SaveCopyAs( savePath );
  }
  catch (Exception ex)
  {
         Logger.Error( "Error creating spreadsheet: {0}", ex.Message );
  }
  finally
  {
      // Cleanup
  }
  </code></pre>
  
  <p>This runs nicely, saves the sheet into the savePath. However, if I change SaveCopyAs() to</p>
  
  <pre><code>SaveAs( savePath, 
          Excel.XlFileFormat.xlWorkbookNormal, 
          Type.Missing,
          Type.Missing, 
          false, 
          false, 
          XlSaveAsAccessMode.xlNoChange,
          Type.Missing, 
          Type.Missing, 
          Type.Missing, 
          Type.Missing, 
          Type.Missing );
  </code></pre>
  
  <p>then the application gets a COMException saying </p>
  
  <pre><code>'C:\//temp/00-04.20.18-24-07-2014/' cannot be accessed. The file may be corrupted,        
  located on a server that is not responding, or read-only.
  </code></pre>
  
  <p>This is a pain since I really need to be saving in .xls format, not .xlsx. Any ideas why this exception occurs for SaveAs()?</p>