So, here's what I'm trying:

new ItemStack(Blocks.skull, 1, 3)

Blocks.skull is the skull, and metadata 3 is the "Head" (the steve head). This crashes my game though.

 

java.lang.NullPointerException: Rendering item
at net.minecraft.item.ItemStack.getItemDamage(ItemStack.java:266)

 

So how do I create an ItemStack of "head"?

At which point do you create that ItemStack? The crash suggests that the Item instance of the ItemStack is null, which shouldn't happen.

 

EntityJoinWorldEvent. I've extended the achievement class to make custom notifications, and I was trying to call one.

 

@SubscribeEvent
public void onJoin(EntityJoinWorldEvent event) {
	if (event.entity instanceof EntityPlayer && !mc.isSingleplayer()) {
		EntityPlayer player = (EntityPlayer) event.entity;
		if (Main.membersList.contains(player.getDisplayName()) 
				&& !player.getDisplayName().equals(mc.thePlayer.getDisplayName())) {
			alert.sendAlertWithItem("A clan member joined!", player.getDisplayName() + " is now online.", -1, new ItemStack(Blocks.skull, 1, 1));
		}
	}
}

Huh, that is really weird. I doubt that is the issue though. Does the error go away if you remove that particular method? If not, post it.

 

I changed it to a different block and it works fine.

 

new ItemStack(Blocks.wool, 1, 1));

 

Sorry, which method did you need?

Oh right, I forgot. In 1.7 some stuff about Blocks and Items changes, so some Blocks which are "technical" blocks (you never get them in your inventory) don't have an ItemBlock anymore, hence the NPE.

Use Items.skull.

 

Exactly right, thanks!