bad argument #2 to 'string.sub' (integer expected, got nil)
stack traceback:
[C]: in function 'string.sub'
/EsoUI/Libraries/Globals/Localization.lua:165: in function 'ZO_CommaDelimitDecimalNumber'
(tail call): ?
user:/AddOns/ShowTTCPrice/ShowTTCPrice.lua:184: in function 'Addon.ChangeInventoryPrice'
user:/AddOns/ShowTTCPrice/ShowTTCPrice.lua:240: in function 'setupCallback'
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:2451: in function 'ZO_ScrollList_UpdateScroll'
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:2535: in function 'ZO_ScrollList_MoveWindow'
Options_Audio_IntroMusicDropdownDropdownScrollScrollBar_ValueChanged:3: in function '(main chunk)'
[C]: in function 'SetValue'
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:184: in function 'OnScrollAnimationUpdate'

bad argument #2 to 'string.sub' (integer expected, got nil)
stack traceback:
[C]: in function 'string.sub'
/EsoUI/Libraries/Globals/Localization.lua:165: in function 'ZO_CommaDelimitDecimalNumber'
|caaaaaa<Locals> amount = 3238, wholeAmount = 3238, amountString = 3238, LITERAL_MATCH = T </Locals>|r
(tail call): ?
user:/AddOns/ShowTTCPrice/ShowTTCPrice.lua:184: in function 'Addon.ChangeInventoryPrice'
|caaaaaa<Locals> control = ud, slot = [table:1]{sellPrice = 4, isJunk = F, traitInformation = 0, bagId = 1, quality = 1, launderPrice = 0, slotIndex = 58, TTCstackSellPrice = 3238, specializedItemType = 1750, stolen = F, sellInformation = 0, isEquipped = F, condition = 100, locked = F, bestGamepadItemCategoryName = "Clothier", TTCsellPrice = 16.19, meetsRequirementsToBuy = T, customSortOrder = 1, uniqueId = 92.821228028027, isFromCrownStore = F, statusSortOrder = 0, actorCategory = 0, itemInstanceId = 1567335906, itemType = 40, displayQuality = 1, age = 0, stackSellPrice = 800, stackCount = 200, traitInformationSortOrder = 1, isInArmory = F, sellInformationSortOrder = 1, isGemmable = F, meetsUsageRequirement = T, name = "Kresh Fiber", brandNew = F, requiredLevel = 1, requiredChampionPoints = 0, isPlaceableFurniture = F, storeGroup = 7, isPlayerLocked = F, iconFile = "/esoui/art/icons/crafting_clot...", rawName = "Kresh Fiber^ns", statValue = 0, isBoPTradeable = F, functionalQuality = 1, equipType = 0, stackLaunderPrice = 0}, data = [table:1], bagId = 1, slotIndex = 58, itemLink = "|H0:item:46131:30:1:0:0:0:0:0:...", iType = 40, siType = 1750, sellPriceControl = ud, priceDataTTC = [table:2]{Min = 3, Max = 150, Avg = 34.38, EntryCount = 564, SuggestedPrice = 16.19, AmountCount = 51382}, PreferredPrice = "SuggestedPrice", TTCsellPrice = 16.19 </Locals>|r
user:/AddOns/ShowTTCPrice/ShowTTCPrice.lua:240: in function 'setupCallback'
|caaaaaa<Locals> control = ud, slot = [table:1], currentScene = [table:3]{state = "shown", name = "tradinghouse", disallowEvaluateTransitionCompleteCount = 0, fireCallbackDepth = 0, restoresHUDSceneToggleUIMode = F, wasRequestedToShowInGamepadPreferredMode = F, wasShownInGamepadPreferredMode = F, restoresHUDSceneToggleGameMenu = F} </Locals>|r
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:2451: in function 'ZO_ScrollList_UpdateScroll'
|caaaaaa<Locals> self = ud, windowHeight = 535, activeControls = [table:4]{}, offset = 775.62457275391, IS_REAL_NUMBER = F, activeIndex = 12, numActive = 11, allData = [table:5]{}, visibleDataIndices = [table:6]{1 = 1}, mode = 1, firstInViewVisibleIndex = 15, nextCandidateVisibleIndex = 26, currentDataIndex = 26, dataEntry = [table:7]{typeId = 1}, bottomEdge = 1310.6245727539, controlTop = 1300, uniformControlHeight = 52, dataType = [table:8]{height = 52, selectable = T}, controlPool = [table:9]{m_NextControlId = 12, m_NextFree = 13}, control = ud </Locals>|r
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:2535: in function 'ZO_ScrollList_MoveWindow'
|caaaaaa<Locals> self = ud, value = 775.62457275391 </Locals>|r
Options_Audio_IntroMusicDropdownDropdownScrollScrollBar_ValueChanged:3: in function '(main chunk)'
|caaaaaa<Locals> self = ud, value = 775.62457275391, eventReason = 1 </Locals>|r
[C]: in function 'SetValue'
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:184: in function 'OnScrollAnimationUpdate'
|caaaaaa<Locals> animationObject = ud, progress = 0.0791395008564, scrollObject = ud, value = 775.62457028914 </Locals>|r

function TamrielTradeCentre:FormatNumber(number, decimal)
	local mult = 10 ^ (decimal or 2)
	number = math.floor(number * mult + 0.5) / mult

	local i, j, minus, int, fraction = tostring(number):find('([-]?)(%d+)([.]?%d*)')
	int = int:reverse():gsub("(%d%d%d)", "%1,")
	return minus .. int:reverse():gsub("^,", "") .. fraction
end