i think it may be is a bug

[imfox]

namespace Game 
{
    public class KLASS{
        public static string ASTATIC = "im fox"; //error
        public KLASS(){}
        public void on(){}
    }
    public class KLASS2 : KLASS{
        public KLASS2()
        {
            on();
        }
    }
    public class Start
    {
        public static void Main()
        {
            new KLASS2();
        }
    }
}

↑ this will be wrong!

↓ no wrong , but can't init this static menber

namespace Game
{
    public class KLASS{
        public static string ASTATIC;
        public KLASS(){ ASTATIC = "im fox"; }
        public void on(){}
    }

    public class KLASS2 : KLASS{
        public KLASS2()
        {
            on();
        }
    }

    public class Start
    {
        public static void Main()
        {
            new KLASS2();
        }
    }
}

Note you also have the static initialiser block...

class K
{
  static {
    // Directives
  }
}