What the heck I am getting for this recommended reduced to minimum code:
package com.codegym.games.minesweeper;
import com.codegym.engine.cell.*;

public class MinesweeperGame extends Game{
    private static final int SIDE = 9;
    //private GameObject [][] gameField;

    public void initialize(){


    //private void createGame(){
    //      int j;
    //      int i;
    //      for (j=0;j<SIDE;j++){
    //        for (i=0;i<SIDE;i++){
    //         gameField [i+1][j+1] = new GameObject();
             //gameField [i+1][j+1] = new GameObject(x,y);
    //        }
    //    }

    //public static void main (String[] args){
    //   MinesweeperGame gameinit = new MinesweeperGame();
    //   }
I reduced the code down to step 1 - just to see what was wrong later at step 4 when, in the best case, the same 1-cell screen was rendered at Step 4, although Step 3 was passed. It looks like the compiler is inconsistent, or the classes in the imported packages are changed. MacOS BigSur 11.6.1 (20G224) for just in case.