Attempt to call a userdata value,what does that mean?

I got a error on line 21 saying Workspace.Part.SurfaceGui.Start.Script:21: attempt to call a userdata value What does it mean?

part = script.Parent
frame = script.Parent.Parent.Frame
clicked = false
part.MouseButton1Click:connect(function()
---------------Debounce------------------
 if clicked == false--Checks if clicked is false(Which it should be,because it already been set false)
	then 
	clicked = true-- Since it false it will turn it true(so we know it's already been clicked)

----------------Fade Out------------------
	for fo = 0,10 do
		wait(0.1)
		part.BackgroundTransparency = fo/10--You need to divide to get the precise number(Other way won't work)
		part.TextTransparency = fo/10
		if fo/10 ==1
			then
			part.Visible = false
			clicked = false --Turns it false,so it you won't able to click it.
		 frame.Visible = true
--------------The frame--------------------
 frame:TweenSize(UDim2.new(0, 0,0, 500)"Out","Quad","1","false")

		end
		end	
	end
	
end)

edited line 21

 frame:TweenSize(UDim2.new(0, 0,0, 500),"Out","Quad",1,false)

You can try this and try it, though it should work.

Using the 1 and dis-including the false or true statement will throw an error of comparing to user data. Also the nil.

                                       **USE LOCALSCRIPT**

Also TWEEN TUTORIAL

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