Scripting error in animated door, makes door handle disappear and no movement. (?)

I'm trying to make an animated door (not one that teleport open) but need help as I am really inexperienced with code and practically new to coding.

Code:

function OnClick()
 script.Parent.Transparency = 1
 script.Parent.CanCollide = false
 script.Parent.Parent.OPEN1.Transparency = 0
 script.Parent.Parent.OPEN1.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN1.Transparency = 1
 script.Parent.Parent.OPEN1.CanCollide = false
 script.Parent.Parent.OPEN2.Transparency = 0
 script.Parent.Parent.OPEN2.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN2.Transparency = 1
 script.Parent.Parent.OPEN2.CanCollide = false
 script.Parent.Parent.OPEN3.Transparency = 0
 script.Parent.Parent.OPEN3.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN3.Transparency = 1
 script.Parent.Parent.OPEN3.CanCollide = false
 script.Parent.Parent.OPEN4.Transparency = 0
 script.Parent.Parent.OPEN4.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN4.Transparency = 1
 script.Parent.Parent.OPEN4.CanCollide = false
 script.Parent.Parent.OPEN5.Transparency = 0
 script.Parent.Parent.OPEN5.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN5.Transparency = 1
 script.Parent.Parent.OPEN5.CanCollide = false
 script.Parent.Parent.OPEN6.Transparency = 0
 script.Parent.Parent.OPEN6.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN6.Transparency = 1
 script.Parent.Parent.OPEN6.CanCollide = false
 script.Parent.Parent.OPEN7.Transparency = 0
 script.Parent.Parent.OPEN7.CanCollide = true
 wait(1.5)
 script.Parent.Parent.OPEN7.Transparency = 1
 script.Parent.Parent.OPEN7.CanCollide = false
 script.Parent.Parent.OPEN8.Transparency = 0
 script.Parent.Parent.OPEN8.CanCollide = true
 wait(1.5)
end

script.Parent.ClickDetector.MouseClick:Connect(OnClick)

"OPEN?" These are individual parents in studio, not grouped together. There is other scripts obviously for closing the door and opening it the other way, but they're all based around this.

This code just makes the door handle disappear.

Any tips and hints on how to fix this will be appreciated! Thank you!

So this is a very messy way to go about this. To make your script more simple, you can place all the parts that you want to become transparent inside a folder inside the model. Then use this script outside of the folder in the same model:

local DoorsFolder = script.Parent.FolderName -- Change FolderName to the name of your folder
local Doors = DoorsFolder:GetChildren() -- This places all children of the folder inside a table
local LastDoor = nil
local function OnClick()
	for i, v in ipairs(Doors) do
		if LastDoor == nil then
			return
		else
			LastDoor.Transparency = 1
			LastDoor.CanCollide = false
		end
		v.CanCollide = true
		v.Transparency = 0
		LastDoor = v
		wait(1.5)
	end
end

script.Parent.MouseDetectorPart.ClickDetector.MouseClick:Connect(OnClick()) --Change script.Parent.MouseDetectorPart to your clickdetector directory

In this answer, I'm using a for loop. I don't know if this will fix our problem but, it's worth a shot.

Since you are new to roblox scripting, I will explain how it works through the script.

local open = {script.Parent.Parent.OPEN1, script.Parent.Parent.OPEN2, script.Parent.Parent.OPEN3, script.Parent.Parent.OPEN4, script.Parent.Parent.OPEN5, script.Parent.Parent.OPEN6, script.Parent.Parent.OPEN7, script.Parent.Parent.OPEN8}
--This is a table. These hold information.

function OnClick()
	for i, door in pairs(open) do --We are looping through or passing through everything in the table we already defined before.
		wait(0.1)
		door.Transparency = 0
		door.CanCollide = true
		if i ~= 1 then --If the door we are looping through is not the first, then..
			local recentDoor = open[i - 1] --The door before
			recentDoor.Transparency = 1
			recentDoor.CanCollide = false
		end
	end
end

script.Parent.ClickDetector.MouseClick:Connect(onClick)

Hope this helped! Don't forget to accept the answer if it did!!