attempt to perform arithmetic (add) on nil and number?

hi,so i have a ice spike script, and i dont get why im getting an error,I would be very grateful if someone wrote what was wrong

ServerScriptService.Ice_Trail_Server:38: attempt to perform arithmetic (add) on nil and number

local CS = game:GetService("CollectionService")
local RS = game.ReplicatedStorage

local NumberOfModel = 3

local Model = 
	{}
DistApart1 = 6
DistHeight1 = 3.452

DistApart2 = 5
DistHeight2 = 4.553

DistApart3 = 5
DistHeight3 = 5.57

local FreezeTime = 5

----- Functions ------ 
local function IceTrailSpike(Object,PlayerName,PartNum)
	Object.Touched:Connect(function(hit)
		Object.CanCollide = true
		if hit.Parent:FindFirstChild("Humanoid") and not CS:HasTag(hit.Parent, "Freeze"..PlayerName) then 
			CS:AddTag(hit.Parent,"Freeze"..PlayerName)
			hit.Parent.Humanoid:TakeDamage(10)
			hit.Parent.HumanoidRootPart.Anchored = true 
			wait(FreezeTime + (0.7*PartNum))
			hit.Parent.HumanoidRootPart.Anchored = false
		end
	end)
end

-- Function 2 -- 

local function IceModelLocation (Player,AttModel,PartCount,DistAdd,RayPos)

	local HRP = Player.Character:WaitForChild("HumanoidRootPart")
	local Ice_Location = CFrame.new(HRP.Position) * ( (Model["DistApart"..PartCount]+DistAdd)*HRP.CFrame.LookVector)
	AttModel.CFrame = CFrame.new(Vector3.new(Ice_Location.X,(RayPos.Y+Model["DistHeight"..PartCount]),Ice_Location.Z))*CFrame.Angles(0,math.rad(HRP.Orientaion.Y),0)
	AttModel.Anchored = true 
	AttModel.Glow.Anchored = true 

end


-- Remote Event -- 
RS.Ice_Trail_Att.OnServerEvent:Connect(function(Player)
	local Debounce = workspace:FindFirstChild("Ice_Trail".. Player.Character.Name)
	local  HRP = Player.Character.HumanoidRootPart
	local groundDistanceRay = Ray.new(HRP.Position,Vector3.new(0,-500,0))
	local Hit, pos = workspace:FindPartOnRay(groundDistanceRay,HRP.Parent)

	local IceAtt_Group = Instance.new("Model",workspace)
	IceAtt_Group.Name = "Ice_Trail_Att"..Player.Character.Name
	local DistAdd = 0 
	-- Part1 -- 
	CS:AddTag(Player.Character, "Freeze"..Player.Name)
	for Part = 1,NumberOfModel do

		local IceModel = RS.Ice_Trail.SPIKE_Model["SPIKES"..Part]:Clone()
		IceTrailSpike(IceModel,Player.Character.Name)



		IceModelLocation(Player,IceModel,Part,DistAdd,pos)
		wait()
		IceModel.Transparecy = 0.2
		DistAdd = DistAdd + Model["DistApart"..Player]

	end
	wait(FreezeTime)
	for Part2 = 1,NumberOfModel do
		local IceModel = workspace["Ice_Trail_Att_"..Player.Character.Name]["SPIKES"..Part2]
		local BG = workspace["Ice_Trail_Att_"..Player.Character.Name]["SPIKES"..Part2].BG.Decal
		local Glow = workspace["Ice_Trail_Att_"..Player.Character.Name]["SPIKES"..Part2].Glow
		local TweenService = game:GetService("TweenService")
		local Goal = {}
		Goal.Transparency = 1
		-- Ice Model
		local tweenInfo = TweenInfo.new(3)
		local IceTween = TweenService:Create(IceModel, tweenInfo, Goal)
		-- Background Model
		local tweenInfo = TweenInfo.new(3)
		local BGTween = TweenService:Create(BG, tweenInfo, Goal)
		-- Glowing Model
		local tweenInfo = TweenInfo.new(3)
		local GlowTween = TweenService:Create(Glow, tweenInfo, Goal)
		GlowTween:Play()
		IceTween:Play()
		IceModel.CanCollide = false
		BGTween:Play()
		wait(0.5)
	end
	wait(1)
	workspace["Ice_Trail_Att_"..Player.Character.Name]:Destroy()
	for _, object in pairs(CS:GetTagged("Freeze"..Player.Character.Name)) do

		CS:RemoveTag(object,"Freeze"..Player.Character.Name)
	end
end)
	

#maybe try this? 'o'

-- Hello there 'o'
local HRP = Player.Character:WaitForChild("HumanoidRootPart")
local Ice_Location = CFrame.new(HRP.Position) + ( (Model["DistApart"..PartCount]+DistAdd)*HRP.CFrame.LookVector)

#if that didn't work try this

-- Hello there 'o'
local HRP = Player.Character:WaitForChild("HumanoidRootPart")
local Ice_Location = CFrame.new(HRP.Position) * ( (Model["DistApart"..PartCount]+DistAdd)*HRP.CFrame.LookVector)