[TestMethod]
public void TestForMigraDocBugReport()
{
    var paragraphFormat = new ParagraphFormat();

    foreach (var border in paragraphFormat.Borders)
    {
        Trace.WriteLine(border.ToString()); // or whatever
    }
}

public Border Current
{
   get
   {
      IEnumerator enumerator = _ht.GetEnumerator();
      enumerator.Reset();
      for (int i = 0; i < _index + 1; i++)
      {
         enumerator.MoveNext();
      }

      /* remove return ((DictionaryEntry)enumerator.Current).Value as Border; */
      /* instead : */
      return ((KeyValuePair<string, Border>)enumerator.Current).Value as Border;
   }
}