Why can't it tell the value is there when it clearly is?

First: why are you connecting two things to the same event?

That's bound to be confusing. In this case, it's likely the cause of an error, since if the second one acts first, there won't be a leaderstats objects (when it acts -- though there will be immediately after, as you are observing).

To fix that, we can write the second one using Player:WaitForChild("leaderstats"):WaitForChild("Level").Changed.

Or we can just use one event.

Here are other issues you should address:

• Use second parameter of Instance.new to shorten things up
• Use whitespace -- no reason to bunch your code up and make it unreadable
• No need to parent leaderstats twice
• Pointless repeat until loop since the condition will always pass since you just made the leaderstats object (and nothing can change that in the middle since it's local)
• Use a lowercase player if you're going to use other lowercase variable names.
• Don't use math.huge ever.

game.Players.PlayerAdded:connect(function(player)
	local leaderstats = Instance.new("StringValue", player)
	leaderstats.Name = "leaderstats"
	local lvl = Instance.new("IntValue", leaderstats)
	lvl.Name = "Level"

	lvl.Changed:connect(function()
		local light = Instance.new("PointLight", player.Character.Torso)
		light.Brightness = 60
		light.Color = Color3.new(255,225,0)
		local Debris = game:GetService("Debris")
		Debris:AddItem(light, 5)
	end)
end)

You should be careful of lvl changing while the Character doesn't have a torso though.

The following would be safer:

if player.Character and player.Character:FindFirstChild("Torso") then
	local light = Instance.new ......