infinite yield on something that exists?

05:01:18.679 - Infinite yield possible on 'Workspace.Infl_uenced.UpperTorso:WaitForChild("Small Backpack")'

although it does in fact exist in uppertorso?

heres whats on line 96 (Where the error occurs)

            if GoldAmount.Value >= Item.ItemPrice.Value then
                if player.UserStats.OwnedBackpack.Value ~= Item then

                local Character = player.Character
                local backpack = Item.ItemName.Value

                if oldBag ~= nil then 
                    Character["UpperTorso"]:WaitForChild(oldBag) -- the specified line which it occurs on
                    Character["UpperTorso"][oldBag]:Destroy()
                end

                local backpackPart
                if game.ReplicatedStorage.BackpackLib:FindFirstChild(backpack) then
                    print('found backpack')
                    backpackPart = game.ReplicatedStorage.BackpackLib[backpack]:Clone()
                else
                    print(backpack)
                end

                backpackPart.CanCollide = false
                backpackPart.Parent = Character["UpperTorso"]

                local Weld = Instance.new("Weld", backpackPart)
                Weld.Part0 = Character["UpperTorso"]
                Weld.Part1 = backpackPart
                if backpack == "Starter Backpack" then
                    Weld.C1 = CFrame.new(0, -.2, .5) * CFrame.Angles(0,math.pi,0)
                else
                    Weld.C1 = CFrame.new(0, .2, -.5)
                end
                GoldAmount.Value = GoldAmount.Value - Item.ItemPrice.Value
                player.UserStats.OwnedBackpack.Value = Item.ItemName.Value
                player.UserStats.OwnedBackpackStorage.Value = BackpackModule["BackpacksData"][Item.ItemName.Value][1]