A bug has appeared up from the latest update to the Valhalla map.
If you go to the iceberg islands and you access your inventory that has a large number of items or if you check your inventory to many times this error may appear:
So this is a notice to be careful when traveling down there for supplies.
Note: There seems to be only one other case of this happening on another server: Link here
On our server I have known of 3 people, including myself that have had the same bug/crash.