Unknown lua error

[Diesosoon]

I keep getting

EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:621: operator < is not supported for number < nil
stack traceback:
	EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:621: in function 'ZO_StoreManager:HasEnoughCurrencyToBuyItem'
	EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:605: in function 'ZO_StoreManager:SetUpBuySlot'
	EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:87: in function 'setupCallback'
	EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:1462: in function 'ZO_ScrollList_UpdateScroll'
	(tail call): ?
	(tail call): ?
	EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:1222: in function 'ZO_ScrollList_Commit'
	EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:458: in function 'ZO_StoreManager:ApplySort'
	EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:539: in function 'ZO_StoreManager:UpdateList'
	EsoUI/Ingame/StoreWindow/Keyboard/StoreWindow_Keyboard.lua:30: in function 'callback'

Any help?