'accessor' adds an accessor not found in interface member 'property'
The implementation of a property in a derived class contains an accessor that was not specified in the base interface.
The following sample generates CS0550:
namespace x { interface ii { int i { get; // add the following accessor to resolve this CS0550 // set; } } public class a : ii { int ii.i { get { return 0; } set // CS0550, no set in interface { } } public static void Main() { } } }