Program: 32615
Project: 32615
Buggy source:
@EventHandler public void onMove(PlayerMoveEvent event){
  final Location from=event.getFrom();
  final Location to=event.getTo();
  final Player player=event.getPlayer();
  Bukkit.getScheduler().runTaskAsynchronously(FunnyGuilds.getInstance(),() -> {
    if (from == null || to == null) {
      return;
    }
    if (from.getBlockX() == to.getBlockX() && from.getBlockZ() == to.getBlockZ()) {
      return;
    }
    MessagesConfig m=Messages.getInstance();
    User user=User.get(player);
    Region region=RegionUtils.getAt(to);
    if (region == null && user.getEnter()) {
      user.setEnter(false);
      region=RegionUtils.getAt(from);
      if (region != null) {
        Guild guild=region.getGuild();
        player.sendMessage(m.regionLeave.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()));
      }
    }
 else     if (!user.getEnter() && region != null) {
      Guild guild=region.getGuild();
      if (guild == null || guild.getName() == null) {
        return;
      }
      user.setEnter(true);
      if (guild.getMembers().contains(user)) {
        player.sendMessage(m.regionEnter.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()));
        return;
      }
      player.sendMessage(m.notificationOther.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()));
      if (player.hasPermission("String_Node_Str")) {
        return;
      }
      if (user.getNotificationTime() > 0 && System.currentTimeMillis() < user.getNotificationTime()) {
        return;
      }
      NotificationBar.set(player,m.notificationOther.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()),1,Settings.getConfig().regionNotificationTime);
      for (      User u : guild.getMembers()) {
        if (u.getName() == null) {
          continue;
        }
        Player member=Bukkit.getPlayer(u.getName());
        if (member == null) {
          continue;
        }
        NotificationBar.set(member,m.notificationMember.replace("String_Node_Str",player.getName()),1,Settings.getConfig().regionNotificationTime);
      }
      user.setNotificationTime(System.currentTimeMillis() + 1000 * Settings.getConfig().regionNotificationCooldown);
    }
  }
);
}

Fixed version (ground truth):
@EventHandler public void onMove(PlayerMoveEvent event){
  final Location from=event.getFrom();
  final Location to=event.getTo();
  final Player player=event.getPlayer();
  Bukkit.getScheduler().runTaskAsynchronously(FunnyGuilds.getInstance(),() -> {
    if (from == null || to == null) {
      return;
    }
    if (from.getBlockX() == to.getBlockX() && from.getBlockZ() == to.getBlockZ()) {
      return;
    }
    MessagesConfig m=Messages.getInstance();
    User user=User.get(player);
    Region region=RegionUtils.getAt(to);
    if (region == null && user.getEnter()) {
      user.setEnter(false);
      region=RegionUtils.getAt(from);
      if (region != null) {
        Guild guild=region.getGuild();
        player.sendMessage(m.regionLeave.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()));
        FunnyGuilds.getInstance().getServer().getScheduler().runTaskLaterAsynchronously(FunnyGuilds.getInstance(),() -> {
          if (Settings.getConfig().createStringMaterial.equalsIgnoreCase("String_Node_Str")) {
            EntityUtil.despawn(guild,player);
          }
        }
,40L);
      }
    }
 else     if (!user.getEnter() && region != null) {
      Guild guild=region.getGuild();
      if (guild == null || guild.getName() == null) {
        return;
      }
      user.setEnter(true);
      FunnyGuilds.getInstance().getServer().getScheduler().runTaskLaterAsynchronously(FunnyGuilds.getInstance(),() -> {
        if (Settings.getConfig().createStringMaterial.equalsIgnoreCase("String_Node_Str")) {
          EntityUtil.spawn(guild,player);
        }
      }
,40L);
      if (guild.getMembers().contains(user)) {
        player.sendMessage(m.regionEnter.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()));
        return;
      }
      player.sendMessage(m.notificationOther.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()));
      if (player.hasPermission("String_Node_Str")) {
        return;
      }
      if (user.getNotificationTime() > 0 && System.currentTimeMillis() < user.getNotificationTime()) {
        return;
      }
      NotificationBar.set(player,m.notificationOther.replace("String_Node_Str",guild.getName()).replace("String_Node_Str",guild.getTag()),1,Settings.getConfig().regionNotificationTime);
      for (      User u : guild.getMembers()) {
        if (u.getName() == null) {
          continue;
        }
        Player member=Bukkit.getPlayer(u.getName());
        if (member == null) {
          continue;
        }
        NotificationBar.set(member,m.notificationMember.replace("String_Node_Str",player.getName()),1,Settings.getConfig().regionNotificationTime);
      }
      user.setNotificationTime(System.currentTimeMillis() + 1000 * Settings.getConfig().regionNotificationCooldown);
    }
  }
);
}