Solved Inventory click event error

i am coding a ban gui plugin but when i tested it i got this error

Code (Text):

public class baninventoryevent implements Listener {

    BanGUI plugin;

    public baninventoryevent(BanGUI plugin) {
        this.plugin = plugin;
    }

    @EventHandler
    public void onMenuClick(InventoryClickEvent e) {
        Player player = (Player) e.getWhoClicked();

        if (e.getClickedInventory().getTitle().equalsIgnoreCase(ChatColor.RED + "BanGUI")) {
            if (e.getCurrentItem().getType() == Material.PLAYER_HEAD) {
                Player whoToBan = player.getServer().getPlayer(e.getCurrentItem().getItemMeta().getDisplayName());

                plugin.openBanReason(player, whoToBan);
            }
        }else if (e.getClickedInventory().getTitle().equalsIgnoreCase("Reasons")) {
            switch (e.getCurrentItem().getType()){
                case IRON_SWORD:
                    String name = e.getClickedInventory().getItem(4).getItemMeta().getDisplayName();
                    player.getServer().getBanList(BanList.Type.NAME).addBan(e.getClickedInventory().getItem(4).getItemMeta().getDisplayName(), "Using combat hacks to an unfair adventage", null, player.getDisplayName());
                    player.sendMessage(ChatColor.RED + "Banned, Thanks for banning and help the server");
                    break;
                case BARRIER:
                    plugin.openGUI(player);
                    break;
            }
        }


        e.setCancelled(true);
    }
}


 

Please help

 

I have done looked at line 33 on the code and i didnt see nothing wornge

EDITED: i am new to coding so ya dont hurt me

 

String name = e.getClickedInventory().getItem(4).getItemMeta().getDisplayName();