Run script help? (bump)

Can you help me please? i inserted it into the starter pack on a local script with a animation inside of it i also has this error: Players.Tommytherox.Backpack.Run:1:attempt to index field 'Character' (a nil value) please help :(

game.Players.LocalPlayer.Character.Humanoid.WalkSpeed = "50"
local playr = game.Players.LocalPlayer
local mouse = playr:GetMouse()
local animation = script:WaitForChild("Animation")
local uis = game:GetService("UserInputService")
local animationTrack = playr.Character.Humanoid:LoadAnimation(animation)

function run(key,gp)
    if key.KeyCode == Enum.KeyCode.Q and gp == false then -- so it doesn't run when typing in chat etc.
        animationTrack:Play()
        script.Fwoosh:Play()
        game.Players.LocalPlayer.Character.Humanoid.WalkSpeed = "250"
    end
end

uis.InputBegan:connect(run)

function dont(key)
    if key.KeyCode == Enum.KeyCode.Q and gp == false then
    animationTrack:Stop()
        game.Players.LocalPlayer.Character.Humanoid.WalkSpeed = "50" --how fast you will walk
    end
end

uis.InputEnded:connect(dont)

wait()
local animationTrack = playr.Character.Humanoid:LoadAnimation(animation)