A silly question - are you trying it in Auridon? It wont work in different zones because there are no image paths.
Make a small change:
Lua Code:
local function QuestMaps()
local zoneIndex = GetCurrentMapZoneIndex()
local imgQuests = questZone[zoneIndex]
if type(imgQuests) == "string" then
image:SetTexture(imgQuests)
tlw:SetHidden(false)
else
tlw:SetHidden(true)
end
end