title: FileDialouge Filter type not accepting .tiproj
body: <p>I am trying to filter the file type in the openfiledialouge but it is not accepting .tiproj it saying invalid file type.</p>
  
  <pre><code> Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
  
                    dlg.DefaultExt = ".tiproj";
                    dlg.Filter = "*.tiproj";
  </code></pre>