Why can't Roblox find the HumanoidRootPart for my character?

I'm trying to make a script where it saves your position so you can rejoin in the same place. The only issue is, no matter what I do the script can't find the HumanoidRootPart. Script:

--aurqore was here
local datastore = game:GetService("DataStoreService")
local positionds = datastore:GetDataStore("Position")
game.Players.PlayerAdded:Connect(function(plr)
	local playerds = positionds:GetAsync(plr.UserId)
	local lastpos
	if(playerds) then
		plr.CharacterAdded:Connect(function(char)
			wait(3)
			char.HumanoidRootPart.Position = Vector3.new(playerds.x,playerds.y,playerds.z)
			return
		end)
	end
	plr.CharacterAdded:Connect(function(char)
		while true do
			wait(.1)
			local humanoidrootpart = char.HumanoidRootPart
			if humanoidrootpart then
				print("found")
				lastpos = {
					x = humanoidrootpart.Position.X,
					y = humanoidrootpart.Position.Y,
					z = humanoidrootpart.Position.Z
				}
			end
		end
	end)
	game.Players.PlayerRemoving:Connect(function(plr2)
		if plr.UserId == plr.UserId then
			positionds:SetAsync(plr.UserId,lastpos)
		end
	end)
end)

The output isn't printing "found" and when I leave it says that argument 2 is nil.