I'm sure the Ruby block is not a C # delegate.
If you pass the delegate to Ruby, you must call it through the Invoke method for the delegate.
Here is a sample code:
var rt = Ruby.CreateRuntime();
var eng = rt.GetEngine("rb");
eng.Execute(@"
class Blocktest
def test(block)
block.Invoke('HELLO From IronRuby')
end
end
");
dynamic ruby = eng.Runtime.Globals;
dynamic t = ruby.Blocktest.@new();
t.test(new Action<string>(Console.WriteLine));
# ruby ​​... .