Weird Concurrent Modification Exception

For some reason I'm getting a Concurrent Modification Exception on this method anyone know on how or why?

Code:java

  @EventHandler
    public void onNPCInteract(PlayerInteractEntityEvent event) {
        Player player = event.getPlayer();
        Iterator<NPC> iterator = npcs.iterator();
        while (iterator.hasNext()) {
            NPC npc = iterator.next(); //<--- throws exception
            if (event.getRightClicked() == npc.getEntity()) {
                Bukkit.getServer().getPluginManager().callEvent(new PlayerInteractNPCEvent(player, npc));
            }
        }
    }

 

if i recall correctly this exception is called from interator being modifyed at same time so here you can find a solutin

 

MCCoding What is it you're iterating over? Do you modify it during iteration? Do you really need to iterate?

 

what about posting stacktrace?

 

mine-care AdamQpzm the problem is that when I remove a NPC in the event I get ate exception but if I were to use a for loop I also get the exception, is there any way around this?

 

MCCoding either you asynchronously modify the collections, or the PlayerInteractNPCEvent modifies the collection.