Error : Bad argument @ 'addEventHandler' [Expected element at argument, got nil]

[ajobr]

Esse erro está acontecendo no meu script já o revisei diversas vezes e não consigo encontrar o erro...  Esse erro aparece nos dois 'addEventHandler' a seguir.

local dxfont0_fonte = dxCreateFont("font/fonte.ttf", 10)
local dxfont1_fonte = dxCreateFont("font/fonte.ttf", 35)

local screenW, screenH = guiGetScreenSize()
local resW, resH = 1360,768
local x, y = (screenW/resW), (screenH/resH)

--math.abs(math.sin(getTickCount()/300))*255)

function isEventHandlerAdded( sEventName, pElementAttachedTo, func )
	if
		type( sEventName ) == 'string' and
		isElement( pElementAttachedTo ) and
		type( func ) == 'function'
	then
		local aAttachedFunctions = getEventHandlers( sEventName, pElementAttachedTo )
		if type( aAttachedFunctions ) == 'table' and #aAttachedFunctions > 0 then
			for i, v in ipairs( aAttachedFunctions ) do
				if v == func then
					return true
				end
			end
		end
	end

	return false
end

function dinfo()
    local alpha = interpolateBetween(1, 0, 0, 255, 0, 0, (getTickCount()-tick2)/1000, "Linear")
    dxDrawRectangle(x*0, y*0, x*1360, y*768, tocolor(0, 0, 0, alpha), false)
      dxDrawText("DORMINDO...", screenW * 0.3581, screenH * 0.4336, screenW * 0.7132, screenH * 0.5182, tocolor(255, 255, 255, math.abs(math.sin(getTickCount()/300))*255), x*1.00, dxfont1_fonte, "left", "top", false, false, false, false, false)
end

function renderD()
    if not isEventHandlerAdded("onClientRender", root, dinfo) then
    	addEventHandler("onClientRender", root, dinfo)
    end
end
addEvent("renderD", true)
addEventHandler("renderD", root, renderD)

function closeDxD()
    if isEventHandlerAdded("onClientRender", root, dinfo) then
		removeEventHandler("onClientRender", root, dinfo)
		showCursor(false)
    end
end

function close()
    if isEventHandlerAdded("onClientRender", root, Fenster2[1]) then
        if state == "down" then
            if isCursorOnElement(screenW * 0.6007, screenH * 0.3307, screenW * 0.0279, screenH * 0.0469) then
		        removeEventHandler("onClientRender", root, Fenster2[1])
		        showCursor(false)
            end
        end
    end
end

addEventHandler("onClientGUIClick", Knopf2[4] , close)

function dormir()
    if isEventHandlerAdded("onClientRender", root, Fenster2[1]) then
        if state == "down" then
            if isCursorOnElement(screenW * 0.4110, screenH * 0.4766, screenW * 0.1176, screenH * 0.0521) then
                tick2 = getTickCount()
                destroyElement(Fenster2[1])
                triggerServerEvent("dormir", localPlayer)
		        closeDx()
		        setTimer(function()
		          	closeDxD()
		        end, 30000, 1)
            end
        end
    end
end

addEventHandler("onClientGUIClick", Knopf2[4] , dormir)

function isCursorOnElement( posX, posY, width, height )
  if isCursorShowing( ) then
    local mouseX, mouseY = getCursorPosition( )
    local clientW, clientH = guiGetScreenSize( )
    local mouseX, mouseY = mouseX * clientW, mouseY * clientH
    if ( mouseX > posX and mouseX < ( posX + width ) and mouseY > posY and mouseY < ( posY + height ) ) then
      return true
    end
  end
  return false
end

[DNL291]

knopf2[4] deveria ser um elemento-gui mas não está definido no seu código, e isso retorna nil.