I get an error which I can’t understand in java while getting a user input

import java.util.Scanner;
public class KK {

    public static void main(String[] args) {
    
        Scanner myObj = new Scanner(System.in);
        System.out.println("Enter username");

        String userName = myObj.nextLine();
        System.out.println("Username is: " + userName);

    }

}

This is the error I get

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 

    at ekdum.KK.main(KK.java:4)

Answer

This error normally occurs, if you use eclipse and your source file has errors. If there are any errors the java compiler from eclipse emits code, that throws an error. Try to clean and rebuild