Berserker Necklace [Freezes client]

When you go and talk to the Silver Merchant at home (North-East) and click on the item 'Berserker Necklace', it'll make your client freeze.
Now I made sure that it wasn't just a coincidence that right when I clicked it then the client froze, so I reloaded it and tried again and sure enough the client froze again when I clicked on that item. Now as you freeze, it even says in the description "null" about 5 times.