can not find IncludeScript

[611@codeplex]

hi
i have add reference phpNetCore
but when i use the bellow script to call the php script

 PHP.Core.ScriptContext context = PHP.Core.ScriptContext.CurrentContext;
            context.Output = Console.Out;

            Type lib = typeof(PhalangerLegacy);
            context.IncludeScript("script.php", lib);

            context.Call("hello");

            PhpReference r = context.Call("add", 5, 3);
            Console.WriteLine(r.Value);


            Console.ReadLine();

it says :

 Method not found: 'System.Object PHP.Core.ScriptContext.IncludeScript(System.String, System.Type)'.

and, the point is here , it is work fine when i run the sample , but when i want to call it from winform ,the above error appear.