Why doesn't this work!?!

This code is supposed to send a message to players with permission:

PHP:

public void alerter(PlayerInteractEvent e) {
        if(plugin.getConfig().getBoolean("Send-Alerts")) {
        plugin.alert(ChatColor.GREEN + "[EM] " + ChatColor.DARK_RED
                + e.getPlayer().getDisplayName() + " tryed to use a "
                + ChatColor.GOLD + e.getItem().getType().toString().toLowerCase() + ".");
    }
    }

This is the alert code in the main class AKA plugin:

PHP:

public void alert(String message) {
            for (final Player player : this.getServer().getOnlinePlayers()) {
                if ((player != null) && player.hasPermission("entitymanager.admin")) {
                    player.sendMessage(message);
                }
            }
        }

This is how i use the alerter code:

PHP:

 if (e.getItem().getTypeId() == 384) {
                            if (plugin.getConfig().getBoolean(
                                    "block.Throw.XpBottles")
                                    && !player
                                            .hasPermission("entitymanager.xpbottles")) {
                                e.setCancelled(true);
                                alerter(e);
                                messager(e);
                                return;
                            }
                        }

 

I assume you have a onPlayerInteract event registered; if so you probably just need to spit out debug messages with your variables until you find where the disconnect is.