Why does it say that readyburger is not a valid member of workspace?

My script is when an npc named "Cook2" steps on a part a burger appears, but it says that readyburger is not a valid member of workspace even though it it.

local rb = game.Workspace:FindFirstChild("ReadyBurger")
if rb then
    script.Parent.Touched:Connect(function(hit)
        if hit.Parent.Name == "Cook2" then
            game.Workspace.ReadyBurger.Transparency = 0
        end
    end)
end