Win7, Vs2010 , silverlight 4

Hi, When i try to run this code, it trows exception like that "The type initializer for 'SR' threw an exception." on Workbook.Load().

Code from http://help.infragistics.com/Help/NetAdvantage/Silverlight/2010.2/CLR4.0/html/SL_Getting_Started_with_Infragistics_Excel_Engine.html

private void Button_Click(object sender, RoutedEventArgs e)
{
   OpenFileDialog openfileDialog = new OpenFileDialog();
   Workbook workbook1;
      
   // Open dialog
   if (openfileDialog.ShowDialog() == true)
   {
      // If user selected a file get the stream of that file
      FileStream stream = openfileDialog.File.OpenRead();

      // Load workbook with data
      workbook1 = Workbook.Load(stream);

      stream.Close();
   }   
}