The drop-down list for item types excludes categories when there are none of that type in the relevant shop or inventory container. If you are viewing a category and sell the last item shown, the category name disappears and is replaced by the next available category alphabetically but without actually changing the item display. I find this behavior easiest to reproduce by going on an adventure or two and then to a shop to sell your Treasure items while having at least one spare Weapon in your inventory. 1. Select the Treasure category from the menu. 2. Sell the treasures. 3. When the last treasure is gone from inventory, the category name displayed will no longer be "Treasure" but "Weapon" yet no weapons will appear in the inventory box. While looking at this mislabeled empty box choosing Weapon from the list or clicking on a character's Weapon slot will not re-sort to show weapons until a different category is selected first, as though the client improperly believes you are already viewing the Weapon category. As I recall, this also happens if you equip the last item from a category that you are viewing but I haven't explicitly tested for it.