483 / 550 Errors; How to fix them? (Local Value is of type: ...)

I have a problem with this code. I am getting two different error messages. The first is a: 483 Error And the second is:

550 - ServerScriptService.MaterialScript:68: attempt to index local 'il' (a number value) How do I fix this error, because I need it to be an integer for serialization to put into a Data Store. Any help would be greatly appreciated.

Thanks in advance, Jerry

local DSS = game:GetService("DataStoreService")
local MaterialsDS = DSS:GetDataStore("GameDB", "MaterialsInfo")
local UpdateDS = DSS:GetDataStore("GameDB", "UpdateInfo")
UpdateDS:SetAsync("UpdateValue", 100)
--[[
	Materials have the following Properties:
	
	Material#1
		- Name: String
		- Description: String
		- Icon: path (Str?)
		- Price: Integer (Lowest Currency)
		- Rarity: Integer
			Converted from Number into a word:
				1	-	"Common"
				2 	-	"Uncommon"
				3	- 	"Rare"
				4	-	"Ultra Rare"
				5	-	"Legendary"
				6	-	"Godly"
				7	-	"HACKS" ( Admin Only )
		- Recipe: { Tuple (Id, Amt) (or {} if non existent) ... }
		
--]]

MaterialsDS.Changed:connect(function()
	print("CHANGED")
end)

game.Loaded:Connect(function()
	print("Game Loaded Successfully!")
end)


local iconsPath = workspace.Assets.Icons
local updatePath = 100
local MaterialsList = {
	["0"] = {
		["Name"] = "Wood",
		["Description"] = "Just some basic wood.",
		["Icon"] = iconsPath.StandInTexture,
		["Price"] = 1,
		["Rarity"] = 1,
		["Recipe"] = {},
		["Id"] = 0
		
	},
	["1"] = {
		["Name"] = "Stone",
		["Description"] = "Stone from 7 feet under.",
		["Icon"] = iconsPath.StandInTexture,
		["Price"] = 2,
		["Rarity"] = 1,
		["Recipe"] = {},
		["Id"] = 1
		
	},
	
	["Length"] = 1
}

local ServerUpdatePath = MaterialsDS:GetAsync("UpdateValue")

if workspace.IsServerLoaded.Value == false then
	print(MaterialsList)
	print("Elements in Dictionary: ".. MaterialsList.Length + 1)
	for il=0, MaterialsList.Length, 1 do
		local data = MaterialsDS:GetAsync(il.ToInt()) or nil
		if data == nil or updatePath > ServerUpdatePath then
			
			-- Doesn't Exist in DB, therefore, the server must add it, or if the two versions differ, the client server takes priority,
			-- (and subsequently triggers an event that triggers across all servers that run a function to find the discrepency and apply the new model) (end)
			--  (to their code)(Possibly Automatic Material + Item Updates?!??!!?)
			local val = il.ToInt()
			print(typeof(il))
			-- ERROR: CANNOT STORE DICTIONARY IN DATA STORE. DATA STORES CAN ONLY ACCEPT VALID UTF-8 CHARACTERS
			MaterialsDS:SetAsync(val, MaterialsList[""..val])
			
			print(MaterialsList[""..val].Name.. "did not exist or did not match current standards.")
		
			
			
		elseif data ~= nil or updatePath < ServerUpdatePath then
			-- If it exists, but our update model is inferior to the server's, then we should update our model(end)
			MaterialsList[""..val] = data
			
		end
		
		
		
		end
		
	
	if updatePath > ServerUpdatePath then
		UpdateDS:SetAsync("UpdateValue", updatePath)
		print("Successfully Updated Server Model")
		
	elseif updatePath < ServerUpdatePath then
		updatePath = ServerUpdatePath
		print("Successfully Updated Client Model")
		
	else
		print("Server and Client Models are Compatible!")
	end
	
	print("Done!")
	workspace.IsServerLoaded.Value = true
end