Got this tonight in the reforge shop in SW on my 85 Frost NE DK, happens when i hit the alt key and mouse over a item.

182x SimpleItemLevel/addon.lua:424: Usage: Item:CreateFromBagAndSlot(bagID, slotIndex)
[string "=[C]"]: in function error' [string "@Blizzard_ObjectAPI/Classic/Item.lua"]:17: in function CreateFromBagAndSlot'
[string "@SimpleItemLevel/addon.lua"]:424: in function <SimpleItemLevel/addon.lua:414>
[string "=[C]"]: in function EquipmentFlyout_DisplayButton' [string "@Blizzard_FrameXML/EquipmentFlyout.lua"]:315: in function EquipmentFlyout_UpdateItems'
[string "@Blizzard_FrameXML/EquipmentFlyout.lua"]:231: in function EquipmentFlyout_Show' [string "@Blizzard_FrameXML/EquipmentFlyout.lua"]:561: in function EquipmentFlyout_UpdateFlyout'
[string "@Blizzard_CharacterFrame/Cata/PaperDollFrame.lua"]:2517: in function `PaperDollItemSlotButton_OnEnter'
[string "*PaperDollFrame.xml:44_OnEnter"]:1: in function <[string "*PaperDollFrame.xml:44_OnEnter"]:1>

Locals:
(*temporary) = "Usage: Item:CreateFromBagAndSlot(bagID, slotIndex)"