Solved Another random NullPointerException

Code:java

public HashMap <String, SuperPlayer> players = new HashMap <String, SuperPlayer>();

Code:java

@EventHandler
    public void onJoin(PlayerJoinEvent evt) {
 
        Player p = evt.getPlayer();
 
        // Check if player in players HashMap
 
        if (Main.players.containsKey(p.getName())) {
            p.sendMessage("Profile not found. Creating a profile for you..");
            Main.players.put(p.getName(), new SuperPlayer());
        } else {
            p.sendMessage("Profile found. Loading your profile..");
        }
 
    }

And when player joins, Bukkit throws a NullPointerException.
I have totally no ideas on this issue. How can I solve it?

Problem solved.

I forgot to set the instance of Main class.

*facepalm*

EDIT by Moderator: merged posts, please use the edit button instead of double posting.