Compiler Error CS0533

'derived-class member' hides inherited abstract member 'base-class member'

A base class method is hidden. Check the syntax of your declaration to see if it is correct.

For more information, see base.

The following sample generates CS0533:

// CS0533.cs
namespace x
{
   abstract public class a
   {
      abstract public void f();
   }

   abstract public class b : a
   {
      new abstract public void f();   // CS0533
      // try the following lines instead
      // override public void f()
      // {
      // }

      public static void Main()
      {
      }
   }
}