Can you try this and see what it prints?
local preloadIDTable = {}
local instanceTable = {}
for _, id in ipairs(preloadIDTable) do
local instance = Instance.new("ImageLabel")
instance.Image = "rbxassetid://"..id
table.insert(instanceTable, instance)
end
local contentprovider = game:GetService("ContentProvider")
local success = contentprovider:PreloadAsync(instanceTable)
if success then
print("They're all loaded")
else
warn("Image preload failed.")
end