InsertService GetFreeModels does not work without a server

When calling the method GetFreeModels of InsertService the script will yield before returning “LuaWebService error”. This will always happen as long as NetworkServer does not exist. I am trying to use it in a plugin to get a set of models for a given query.

local insertService = game:GetService'InsertService'
local models = unpack(insertService:GetFreeModels("Tree", 1))

for i = 1, models.TotalCount do
	local model = models.Results[i]
	print("Item #"..i)
	for key,value in pairs(model) do
		print(" " .. key .. ": " .. value)
	end
end

>> LuaWebService error

Edit: Seems to have stopped… perhaps it’s related to “Catalog not available at the moment”?