Why do i get this output (new is not a valid member)?

can someone help me

Material = "Grass"
InProgress = false
SpawnEnabled = false
BrickEnabled = false
TreeEnabled = false

local CoreGui = game:GetService("CoreGui")

self = PluginManager():CreatePlugin()
toolbar = self:CreateToolbar("RobloxMinecraftDK")
button = toolbar:CreateButton("","Baseplate Generator","Baseplate Generator Icon.PNG")
mouse = self:GetMouse()

local GuiCreated = false
local holderGui = Instance.new('ScreenGui',CoreGui)
holderGui.Archivable = false
holderGui.Name = "BGGui"
local holderFrame = Instance.new('Frame',holderGui)
holderFrame.Name = "BGFrame"
holderFrame.Style = "RobloxSquare"
holderFrame.Visible = false
holderFrame.Archivable = false
holderFrame.Size = UDim2.new(1,0,0,200)
holderFrame.BackgroundTransparency = 0
holderFrame.Parent = holderGui

function GenerateBaseplate()
	if InProgress == false then
		InProgress = true
		holderFrame.Generate.Text = "Generating"
		print "Running"
		local Brick = Instance.new("Part",game.Workspace)
		Brick.Anchored = true
		Brick.Name = "Baseplate"
		Brick.Size = Vector3.new(250, 0, 250)
		wait(0.1)
		Brick.Position = Vector3.new(0, 0, 0)
		wait(0.1)
		if SpawnEnabled == true then
			local Spawn = Instance.new("SpawnLocation",game.Workspace)
			Spawn.Anchored = true
			Spawn.Size = Vector3.new(6, 1.2, 6)
			wait(0.1)
			Spawn.TopSurface = "Smooth"
			Spawn.Position = Vector3.new(0, 1,2, 0)
			wait(0.1)
		end
		if Material == "Grass" then
			Brick.BrickColor = BrickColor.new("Camo") --Here
		elseif Material == "Sand" then
			Brick.BrickColor = BrickColor.new("Cool yellow") --Here
		elseif Material == "Ice" then
			Brick.BrickColor = BrickColor.new("Medium blue") -- Here
		end
		wait(0.1)
		local Decal = Instance.new("Decal",Workspace.SpawnLocation)
		wait(0.1)
		Decal.Face = "Top"
		Decal.Texture = "rbxasset://Textures/SpawnLocation.png"
		wait(0.1)
		Brick.Material = Material
		wait(0.1)
		if BrickBut == true then
			local BuildBlock = Instance.new("Part",game.Workspace)
			BuildBlock.Position = Vector3.new(14, 1.2, -32)
			wait(0.1)
			local Truss = Instance.new("TrussPart",game.Workspace)
			Truss.Position = Vector3.new(9, 1.6, -32)
			wait(0.1)
			local Wedge = Instance.new("WedgePart",game.Workspace)
			Wedge.Position = Vector3.new(5, 1.2, -32)
			wait(0.1)
			local CornerWedge = Instance.new("CornerWedgePart",game.Workspace)
			CornerWedge.Position = Vector3.new(1, 1.6, -32)
			wait(0.1)
			local Cylinder = Instance.new("Part",game.Workspace)
			Cylinder.Shape = "Cylinder"
			Cylinder.Position = Vector3.new(-4, 2.6, -32)
		end
		if TreeEnabled == true then
			Val = 0
			while true do
				wait(0.1)
				VectorX = math.random(-125,125)
				VectorZ = math.random(-125,125)
				local Wood = Instance.new("Part",game.Workspace)
				Wood.Size = Vector3.new(2,10,2)
				Wood.BrickColor = BrickColor.new("Reddish brown")
				Wood.Position = Vector3.new(VectorX,0,VectorZ)
				Wood.TopSurface = "Smooth"
				Wood:MakeJoints()
				wait(0.1)
				local Leaf = Instance.new("Part",game.Workspace)
				Leaf.Size = Vector3.new(10,10,10)
				Leaf.BrickColor = BrickColor.new("Bright green")
				Leaf.Position = Wood.Position
				Leaf.TopSurface = "Smooth"
				Leaf.BottomSurface = "Smooth"
				Leaf:MakeJoints()
				Val = Val +1
				if Val == 10 then
					Val = nil
					VectorX,VectorZ = nil
					break
				end
			end
		end
		holderFrame.Generate.Text = "Generate"
		game.Workspace.Camera.CameraType = "Fixed"
		InProgress = false
	end
end

You troll :3

Pfft. I was reading through this script for a minute, them I'm like oh e.e XD