Item Set Bug [Client]

So I was trying to create a new itemset for ( AP Leona :P ), and I was unable to put any items in the set. So I logged out, logged back in and tried again and was unable to put any item in any item set, no matter if I picked an item from the menu, searched by category, or manually searched by name, nor if I clicked the item from the menu or clicked on the item itself then tried adding it. Just a minor bug but still annoying nonetheless. Any help on the situation would be appreciated. Thanks!