Attempt to connect failed: Passed value is not a function?

I was going to make a Spectate Function so you can see other players camera

I keep getting a error saying that it attempted to connect but failed because Passed Value is not a function. Thats not right because i already setup the functions.

Heres my code and the exception happend at line 25 and 26 Which is script.Parent.Parent.Style.Forward.MouseButton1Click:connect(GoForward) script.Parent.Parent.Style.Back.MouseButton1Click:connect(GoBack)

script.Parent.MouseEnter:connect(function()
	script.Parent:TweenPosition(UDim2.new(0,0,0.3,0),"Out","Quad",0.1)
	script.Parent.Parent.Parent.MouseOver:Play()
end)

script.Parent.MouseLeave:connect(function()
	script.Parent:TweenPosition(UDim2.new(0,-20,0.3,0),"Out","Quad",0.1)
end)

players = {}

PChoice = 1

script.Parent.MouseButton1Click:connect(function()
	Spectating = false
	script.Parent.Parent.Parent.MouseClick:Play()
	if script.Parent.Selected == false then
		script.Parent.Selected = true
		script.Parent.Parent.Style.Visible = true
		for i,v in ipairs(Game.Players:GetChildren()) do
			if v.Name ~= game.Players.LocalPlayer.Name then
				table.insert(players,v)
			end
		end
		script.Parent.Parent.Style.Forward.MouseButton1Click:connect(GoForward)
		script.Parent.Parent.Style.Back.MouseButton1Click:connect(GoBack)
	else
		script.Parent.Selected = false
		script.Parent.Parent.Style.Visible = false
		game.Workspace.CurrentCamera.CameraSubject = game.Players.LocalPlayer.Character.Humanoid
	end
end)

while true do
	if game.Players.NumPlayers == 1 then
		script.Parent:TweenPosition(UDim2.new(0,-150,0.3, 0),"In","Quad",0.5)
	else
		script.Parent:TweenPosition(UDim2.new(0,-15,0.3, 0),"Out","Quad",0.5)
	end
	wait()
end

function GoForward()
	PChoice = PChoice + 1
	if PChoice >= #players then
		PChoice = 1
	end
	game.Workspace.CurrentCamera.CameraSubject = players[PChoice].Character.Humanoid
end

function GoBack()
	PChoice = PChoice - 1
	if PChoice <= 1 then
		PChoice = #players
	end
	game.Workspace.CurrentCamera.CameraSubject = players[PChoice].Character.Humanoid
end

Heres the error i got

10:28:27.170 - Attempt to connect failed: Passed value is not a function 10:28:27.170 - Script 'Players.Player2.PlayerGui.Spectate.Button.System', Line 25 10:28:27.170 - Stack End 10:28:27.170 - Attempt to connect failed: Passed value is not a function 10:28:27.170 - Script 'Players.Player2.PlayerGui.Spectate.Button.System', Line 26 10:28:27.170 - Stack End

I'm not sure, but I think the functions these lines connect are below, but they need to be above the codeblock.