[Vault] Runtime AbstractMethodError

Hi everyone! I'm actually trying to make a plugin to give penalties to players using Vault to extort money from players. All seems to work but when I try to use withdrawPlayer() from my variable "econ", an AbstractMethodError is thrown in Minecraft console.

Code:

BlehPenalty.java (main class)

Code:java

 File file;
    private FileConfiguration fileConfig;
 
    private static ArrayList<Player> punished = new ArrayList<Player>();
    private static ArrayList<Player> late = new ArrayList<Player>();
    private static ArrayList<Integer> penalty = new ArrayList<Integer>();
 
    @Override
    public void onEnable() {
        plugin = this;
        log.info("[BlehPenalty] BlehPenalty chargé, fin prêt à coller quelques amendes.");
        if (!setupEconomy() ) {
            log.severe(String.format("[%s] - Disabled due to no Vault dependency found!", getDescription().getName()));
            getServer().getPluginManager().disablePlugin(this);
            return;
        }
        this.loadConfigFile();
    }
 
    private boolean setupEconomy() {
        if (getServer().getPluginManager().getPlugin("Vault") == null) {
            log.info("BLEH");
            return false;
        }
        RegisteredServiceProvider<Economy> rsp = getServer().getServicesManager().getRegistration(net.milkbowl.vault.economy.Economy.class);
        if (rsp == null) {
            log.info("PLOP");
            return false;
        }
        econ = rsp.getProvider();
        return econ != null;
    }
 
    @Override
    public boolean onCommand(CommandSender sender, Command command, String commandLabel, String[] args)    {
        try {
            return Handler.onCommand(sender, command, commandLabel, args);
        } catch (Exception ex) {
            log.severe(ex.toString());
        }
 
        return false;
    }
 
// The rest of my class. Blah blah blah.
 

CommandPay.java (class where Vault is used)

Code:java

public class CommandPay {
 
 
    public static boolean doCommand(CommandSender sender, String[] args) throws Exception {
        if (args.length <= 1) {
            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Utilisation : /bp pay <yes/no>");
        } else {
            UUID target = UUIDFetcher.getUUIDOf(sender.getName());
            Player theplayer = Bukkit.getPlayer(target);
 
            if (BlehPenalty.isPunished(theplayer) || BlehPenalty.isLate(theplayer)) {
 
                if (BlehPenalty.isPunished(theplayer)) {
                    switch (args[1]) {
                        case "yes":
                            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Vous avez payé votre amende avec succès !");
                            EconomyResponse r = BlehPenalty.econ.withdrawPlayer(Bukkit.getOfflinePlayer(target), BlehPenalty.getPenaltyValue(theplayer));
                            if(r.transactionSuccess()) {
                                sender.sendMessage(String.format("You perdez %s et avez désormais %s", BlehPenalty.econ.format(r.amount), BlehPenalty.econ.format(r.balance)));
                            } else {
                                sender.sendMessage(String.format("An error occured: %s", r.errorMessage));
                            }
                            for (Player onlinePlayer : Bukkit.getOnlinePlayers()) {
                                if (onlinePlayer.hasPermission("blehpenalty.penalty")) {
                                    onlinePlayer.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] "+sender.getName()+" vient juste de s'acquitter de son amende !");
                                }
                            }
                        break;
                        case "no":
                            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Vous venez de refuser de payer votre amende !");
                            for (Player onlinePlayer : Bukkit.getOnlinePlayers()) {
                                if (onlinePlayer.hasPermission("blehpenalty.penalty")) {
                                    onlinePlayer.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] ALERTE !! "+sender.getName()+" vient juste de refuser de payer son amende !");
                                }
                            }
                        break;
                        default:
                            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Le paramètre doit être soit \"yes\", soit \"no\" !");
                            break;
                    }
                }
 
                if (BlehPenalty.isLate(theplayer)) {
                    switch (args[1]) {
                        case "yes":
                            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Vous avez payé votre amende avec retard...");
                            BlehPenalty.econ.withdrawPlayer(Bukkit.getOfflinePlayer(target), BlehPenalty.getPenaltyValue(theplayer));
                            for (Player onlinePlayer : Bukkit.getOnlinePlayers()) {
                                if (onlinePlayer.hasPermission("blehpenalty.penalty")) {
                                    onlinePlayer.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] ALERTE !! "+sender.getName()+" vient juste de s'acquitter de son amende en retard...");
                                }
                            }
                            break;
                        case "no":
                            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Vous venez de refuser de payer votre amende !");
                            for (Player onlinePlayer : Bukkit.getOnlinePlayers()) {
                                if (onlinePlayer.hasPermission("blehpenalty.penalty")) {
                                    onlinePlayer.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] ALERTE !! "+sender.getName()+" vient juste de refuser de payer son amende en retard ! Il est dissident !!");
                                }
                            }
                            break;
                        default:
                            sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Le paramètre doit être soit \"yes\", soit \"no\" !");
                            break;
                    }
                }
 
            } else {
                sender.sendMessage(ChatColor.DARK_AQUA+"[BlehPenalty] Vous n'êtes ni amendé ni retardataire, inutile de payer quoi que ce soit donc.");
            }
 
        }
        return true;
    }
 
}
 

Could anyone help me find a solution?
I'll give you my error code after I have took a screen of it.

Otherwise I know my english is not perfect. You probably noted that I'm french so be indulgent please