I am trying to open my editor window via MethodInfo.Invoke but it will not work .

            if (GUI.Button(new Rect(0, 0, 200, 20), "Click Me"))
            {
                Type thisType = typeof(EditorWindow);
                MethodInfo theMethod = thisType.GetMethod("GetWindow", new Type[]{typeof(MyWindow)});
                theMethod.Invoke("GetWindow", new object[]{typeof(MyWindow)});
            }

This works so why cant i get my editor window to show up

if (GUI.Button(new Rect(0, 0, 200, 20), "Click Me"))
            {
                Type thisType = typeof(TestThis);
                MethodInfo theMethod = thisType.GetMethod("Up", new Type[]{typeof(String)});
                theMethod.Invoke("Up", new object[]{" word "});
            }

public class TestThis
{


    public static void Up()
    {
        Debug.Log("Works");
    }

    public static void Up( String T)
    {
        Debug.Log(T);
    }
}

I modified your script to test it and it appears if you change typeof(MyWindow) in the GetMethod call to typeof(Type) it seems to work.

So the resulting line change would look like:

MethodInfo theMethod = thisType.GetMethod("GetWindow", new Type[]{typeof(Type)});

See if that works for you.