Can not select class

Please report bug in issue tracker with more details, thanks. https://youtrack.jetbrains.com/issues/IDEA

My void is red_undeerlined, is it real problem

Your code is missing class declaration.

public class Main {

  public static void main ..... [ rest of your code]

}

Thank You Yann Cebron

It was my first hello world code so i had not defined class. Now it works.