C#

<code>
public class Animal
{
   private bool _HasFur;
   private int _NumberOfLegs;

   public bool HasFur {
      get {
         return _HasFur;
      }
      set {
         _HasFur = value;
      }
   }

   public int NumberOfLegs {
      get {
         return _NumberOfLegs;
      }
      set {
         _NumberOfLegs = value;
      }
   }
}

public class Cat : Animal
{
   private bool _CroppedTail;

   public bool CroppedTail {
      get {
         return _CroppedTail;
      }
      set {
         _CroppedTail = value;
      }
   }
}

public void Main()
{
   object catObject = Activator.CreateInstance(typeof(Cat));

   // This works fine.
   PropertyInfo prop = catObject.GetType().GetProperty("CroppedTail");
   prop.SetValue(catObject, true, null);

   // This throws an Exception
   prop = catObject.GetType().GetProperty("HasFur");
   prop.SetValue(catObject, true, null);             // <--  Exception thrown by this line.
}
</code>