I got an error when executing the script, anyone can help fix it?

Trying to make an ice move for my game, but it keeps giving me this error Error : https://media.discordapp.net/attachments/812374695545667615/815924831198511154/unknown.png

Script:

local ReplicatedStorage = game:WaitForChild("ReplicatedStorage")
local Remote = game.ReplicatedStorage.Events:WaitForChild("IceRemote")



Remote.OnServerEvent:Connect(function(player)
    local Character = player.Character
    local RootPart = Character:WaitForChild("HumanoidRootPart")
    local folder = workspace:FindFirstChild("DebrisFolder") or Instance.new("Folder",workspace)
    folder.Name = "DebrisFolder"

    local Position = Instance.new("BodyVelocity",RootPart)
    Position.MaxForce = Vector3.new(99999999999999999999,99999999999999999999,99999999999999999999)
    Position.P = 300
    Position.Velocity = RootPart.CFrame.LookVector * .1
    game.Debris:AddItem(Position,2)

    local val = -4
    local sizez = 3
    local sizex = 10
    local sideval = .5

    local function Ice()
        local extra = math.random(-11,11)/10
        local Shard = game.ReplicatedStorage.IceRemoteEffects:WaitForChild("IceShard"):Clone()
        local side = math.random(-sideval,sideval)
        up = Shard.Size.Y/2
        local rotate = math.random(0,180)

        local MRo = math.random(99,100)
        if MRo == 99 then
            local SRo = math.random(8,10)/10
            URo = MRo + SRo
        else
            local SRo = math.random(1,3)/10
            URo = MRo + SRo
        end



        Shard.Size = Vector3.new(sizez,sizex,sizez)
        Shard.CFrame = RootPart.CFrame.new(side,-up.val + extra)
        Shard.Parent = folder
        Shard.CFrame = Shard.CFrame * CFrame.fromEulerAnglesXYZ(URo,rotate,0.4)


        val = val - 2
        sizez = sizez + 1
        sizex = sizex + 1
        sideval = sideval + .5
        game.Debris:AddItem(Shard,5)



    spawn(function()
        wait(.5)
        local TweenService = game:GetService("TweenService")

        local TweenInform = TweenInfo.new(
            .3,
            Enum.EasingStyle.Linear,
            Enum.EasingDirection.Out,
            0,
            false,
            0
            )

        local Properties = {
            CFrame = Shard.CFrame * CFrame(0,up * 1.5, 0)
        }

        local Tween = TweenService:Create(Shard,TweenInform,Properties)
            Tween:Play()


    end)


    end


for i = 1,50 do
    Ice()
    wait()
    end







end)