Engine bug reguarding FindFirstChild()?

[Resurrected_Dove (rs_dv)]

Hello, recently i’ve discovered a weird glitch revolving FindFirstChild(). I keep getting this error saying “attempt to index nil with ‘FindFirstChild’” even though the instance is clearly there.
My code is simple, if the script finds a child named “Frame(number)” then it’ll tween the part to it.
If it doesnt, the script will just destroy itself.

local frame = 1
while true do
	if not script.Parent:FindFirstChild("Frame"..frame) then
		script:Destroy()
	end
	if script.Parent:FindFirstChild("Frame"..frame) then
		task.wait(script.Parent:FindFirstChild("Frame"..frame).TimeBetweenFrames.Value - 0.025)
		game:GetService("TweenService"):Create(script.Parent,TweenInfo.new(0.075, Enum.EasingStyle.Linear, Enum.EasingDirection.Out), {CFrame = script.Parent:FindFirstChild("Frame"..frame).Value}):Play()
		frame = frame + 1
	end
	task.wait(0.025)
end

I’ve tried putting a wait to give the instance some time to load, but for some reason it still gives me the error despite being here.
(This is in a viewport by the way.)

[Resurrected_Dove (rs_dv)]

Turns out for some reason the script still runs even though the script was destroyed. That definitely needs some tweaking.

[p49p0 (Panthera)]

regarding* anyway the error means you are calling FindFirstChild on nil or perhaps the instance is destroyed/gone. also

local frame = 1
while true do
	if not script.Parent:FindFirstChild("Frame"..frame) then
		script:Destroy()
	end
	if script.Parent:FindFirstChild("Frame"..frame) then
		task.wait(script.Parent:FindFirstChild("Frame"..frame).TimeBetweenFrames.Value - 0.025)
		game:GetService("TweenService"):Create(script.Parent,TweenInfo.new(0.075, Enum.EasingStyle.Linear, Enum.EasingDirection.Out), {CFrame = script.Parent:FindFirstChild("Frame"..frame).Value}):Play()
		frame = frame + 1
	end
	task.wait(0.025)
end

you didn’t forget to do return after script:Destroy()???
(yes while loops run even after getting destroyed) (i knew this since 2022)

[Resurrected_Dove (rs_dv)]

Yikes, thanks for reminding me. That would of been a big issue in the future.

[BonesIsUseless (Bones)]

you could try a for loop instead so you don’t need to keep track of the ‘frames’ (:FindFirstChild("Frame"..frame))

local TS = game:GetService("TweenService")
local TInfo = TweenInfo.new(0.075, Enum.EasingStyle.Linear, Enum.EasingDirection.Out)

for _, CFrameValue in ipairs(script.Parent:GetChildren()) do
  if CFrameValue:IsA("CFrameValue") then
    local Tween = TS:GetService("TweenService"):Create(script.Parent, TInfo, {
      CFrame = CFrameValue.Value
    })
    Tween:Play()
 -- instead of having wait values for each tween, you could use 'Completed'
    Tween.Completed:Wait()
  end
  task.wait(0.025)
end

@p49p0

you didn’t forget to do return after script:Destroy()???

meant break