Attempt to index nil error with door?

I have made a table in order to reference objects quicker. The problem is that an error occurs where it says, "Attempt to index nil with door1". I am wondering if someone could point out what is wrong so I can fix it.

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait()
local RunService = game:GetService("RunService")
local UserInputService = game:GetService("UserInputService")

local DoorGroup = {
	game.Workspace.ButtonDoor,
	game.Workspace.ButtonDoor1
}

local Door = DoorGroup.PrimeDoor
local DoorPart = Door.Door1
local DoorPrimaryPart = Door.PrimaryPart

local neonpart = Door.Button.Neon

local player = game.Players.LocalPlayer
local event = game.ReplicatedStorage.ToggleDoor
local mouse = player:GetMouse()

local NearDoor = false

RunService.RenderStepped:Connect(function()
	if Player:DistanceFromCharacter(DoorPrimaryPart.Position) < 5 then
		if mouse.Target == DoorPrimaryPart then
			NearDoor = true
			DoorPrimaryPart.EToOpen.Enabled = true
			DoorPrimaryPart.EToOpen2.Enabled = true
		end
	else
		NearDoor = false
		DoorPrimaryPart.EToOpen.Enabled = false
		DoorPrimaryPart.EToOpen2.Enabled = false
	end
end)

UserInputService.InputBegan:Connect(function(Input)
	if Input.UserInputType == 	Enum.UserInputType.Keyboard then
		local Key = Input.KeyCode
		if Key == Enum.KeyCode.E and NearDoor == true then
			event:FireServer()
		end
	end
end)

The error is coming from the lines below. DoorGroup.PrimeDoor does not exist; therefore, you are indexing nil with Door1.

local DoorGroup = {
    game.Workspace.ButtonDoor,
    game.Workspace.ButtonDoor1
}

local Door = DoorGroup.PrimeDoor
local DoorPart = Door.Door1