Error 1109

I've ran it before and it works. Then suddenly it didn't. 

Code: 

import flash.events.Event;
import flash.filters.*;

stop();

//////////////////////Filters///////////////////////
var permGlow:GlowFilter = new GlowFilter();
permGlow.alpha = .5;
permGlow.color = 0xffffff;
permGlow.blurX = 10;
permGlow.blurY = 10;
Journal1.filters = [permGlow];
Journal2.filters = [permGlow];
Journal3.filters = [permGlow];

var myGlow:GlowFilter = new GlowFilter();
myGlow.alpha = 1;
myGlow.color = 0xffffff;
myGlow.blurX = 50;
myGlow.blurY = 50;

//////////////////////Circular Path//////////////////
var angle:Number = 0;
var radius:Number = 170;

var center:Number = 266;
var centery:Number = 140;

stage.addEventListener(Event.ENTER_FRAME,spin);
function spin(e:Event):void
{
Journal1.x = center + Math.sin(angle - 500) * radius;
Journal1.y = centery + Math.cos(angle - 500) * radius;

Journal2.x = center + Math.sin(angle - 100) * radius;
Journal2.y = centery + Math.cos(angle - 100) * radius;

Journal3.x = center + Math.sin(angle + 300) * radius;
Journal3.y = centery + Math.cos(angle + 300) * radius;

angle += .02;
}
////////////////////////Button Click///////////////////////
Journal1.addEventListener(MouseEvent.CLICK, jump_char);
function jump_char(e:MouseEvent):void
{
gotoAndPlay(2);
}

Journal2.addEventListener(MouseEvent.CLICK, jump_place);
function jump_place(e:MouseEvent):void
{
gotoAndPlay(3);
}

Journal3.addEventListener(MouseEvent.CLICK, jump_monster);
function jump_monster(e:MouseEvent):void
{
gotoAndPlay(4);
}
//////////////////////////Hover//////////////////////////
Journal1.addEventListener(MouseEvent.MOUSE_OVER, glow1);
function glow1(e:MouseEvent):void
{
Journal1.filters = [myGlow];
Journal1.addEventListener(MouseEvent.MOUSE_OUT, closeglow);
}

Journal2.addEventListener(MouseEvent.MOUSE_OVER, glow2);
function glow2(e:MouseEvent):void
{
Journal2.filters = [myGlow];
Journal2.addEventListener(MouseEvent.MOUSE_OUT, closeglow);
}

Journal3.addEventListener(MouseEvent.MOUSE_OVER, glow3);
function glow3(e:MouseEvent):void
{
Journal3.filters = [myGlow];
Journal3.addEventListener(MouseEvent.MOUSE_OUT, closeglow);
}
//////////////////////Off Hover/////////////////////////
function closeglow(e:MouseEvent):void
{
Journal1.filters = [permGlow];
Journal2.filters = [permGlow];
Journal3.filters = [permGlow];
}

Error:

TypeError: Error #1009: Cannot access a property or method of a null object reference. at GravityFalls_fla::MainTimeline/spin()