Hi im getting  this fatal error when trying to run WoM
Im running Vista 64

Fatal error:

Error launching World of Minecraft client:

java.util.ConcurrentModificationException

Everything was running ok until i upgraded to Minecraft beta 1.8.

My first solution was to
Uninstall Java
Uninstall Minecraft 1.8 Beta
Uninstall Minecraft Server
Uninstall WoM
restart computer
Install Java
Install Minecraft 1.8 beta
Install Minecraft Server
Install WoM

After this im still getting same Fatal Error. I can still run Minecraft, Mincraft Server and Minecraft classic from browser.

I then went on to http://www.worldofminecraft.com/debug and followed the instructions and this is the outcome when using Command prompt.

Microsoft Windows [Version 6.0.6002]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Paul>cd desktop

C:\Users\Paul\Desktop>cd womtest

C:\Users\Paul\Desktop\WoMTest>cd WoMClient-1.9.0

C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0>java -version
java version "1.6.0_27"
Java(TM) SE Runtime Environment (build 1.6.0_27-b07)
Java HotSpot(TM) Client VM (build 20.2-b06, mixed mode, sharing)

C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0>java -D32 -jar World of Minecraft.exe
Making skin folder: C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0\skins
Making auto-load folder: C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0\lib\auto
Making default folder: C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0\lib\default

Making minecraft folder: C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0\lib\minec
raft
Writing META-INF/CODESIGN.SF
Writing META-INF/CODESIGN.RSA
Writing 2char.png
Writing a/a.class
Writing armor/chain.png
Writing armor/plate.png
Writing char.png
Writing clouds.png
Writing com/mojang/a/a.class
Writing com/mojang/minecraft/a/a.class
Writing com/mojang/minecraft/a/b.class
Writing com/mojang/minecraft/a/c.class
Writing com/mojang/minecraft/a/d.class
Writing com/mojang/minecraft/a/e.class
Writing com/mojang/minecraft/a/f.class
Writing com/mojang/minecraft/a/g.class
Writing com/mojang/minecraft/a/h.class
Writing com/mojang/minecraft/a/i.class
Writing com/mojang/minecraft/a/j.class
Writing com/mojang/minecraft/a/k.class
Writing com/mojang/minecraft/a/l.class
Writing com/mojang/minecraft/a/m.class
Writing com/mojang/minecraft/a/n.class
Writing com/mojang/minecraft/a/o.class
Writing com/mojang/minecraft/a.class
Writing com/mojang/minecraft/b/a/a.class
Writing com/mojang/minecraft/b/a/b.class
Writing com/mojang/minecraft/b/a/c.class
Writing com/mojang/minecraft/b/a.class
Writing com/mojang/minecraft/b/b.class
Writing com/mojang/minecraft/b/c.class
Writing com/mojang/minecraft/b/d.class
Writing com/mojang/minecraft/b/e.class
Writing com/mojang/minecraft/b/f.class
Writing com/mojang/minecraft/b/g.class
Writing com/mojang/minecraft/b/h.class
Writing com/mojang/minecraft/b/i.class
Writing com/mojang/minecraft/b/j.class
Writing com/mojang/minecraft/b.class
Writing com/mojang/minecraft/c/a.class
Writing com/mojang/minecraft/c/b.class
Writing com/mojang/minecraft/c/c.class
Writing com/mojang/minecraft/c/d.class
Writing com/mojang/minecraft/c/e.class
Writing com/mojang/minecraft/c/f.class
Writing com/mojang/minecraft/c/g.class
Writing com/mojang/minecraft/c/h.class
Writing com/mojang/minecraft/c/i.class
Writing com/mojang/minecraft/c/j.class
Writing com/mojang/minecraft/c/k.class
Writing com/mojang/minecraft/c/l.class
Writing com/mojang/minecraft/c/m.class
Writing com/mojang/minecraft/c/n.class
Writing com/mojang/minecraft/c.class
Writing com/mojang/minecraft/d/a.class
Writing com/mojang/minecraft/d/b.class
Writing com/mojang/minecraft/d/c.class
Writing com/mojang/minecraft/d.class
Writing com/mojang/minecraft/e/a.class
Writing com/mojang/minecraft/e/b.class
Writing com/mojang/minecraft/e/c.class
Writing com/mojang/minecraft/e/d.class
Writing com/mojang/minecraft/e/e.class
Writing com/mojang/minecraft/e/f.class
Writing com/mojang/minecraft/e/g.class
Writing com/mojang/minecraft/e/h.class
Writing com/mojang/minecraft/e/i.class
Writing com/mojang/minecraft/e/j.class
Writing com/mojang/minecraft/e/k.class
Writing com/mojang/minecraft/e/l.class
Writing com/mojang/minecraft/e/m.class
Writing com/mojang/minecraft/e/n.class
Writing com/mojang/minecraft/e/o.class
Writing com/mojang/minecraft/e/p.class
Writing com/mojang/minecraft/e/q.class
Writing com/mojang/minecraft/e/r.class
Writing com/mojang/minecraft/e.class
Writing com/mojang/minecraft/Entity.class
Writing com/mojang/minecraft/f.class
Writing com/mojang/minecraft/g.class
Writing com/mojang/minecraft/h.class
Writing com/mojang/minecraft/i.class
Writing com/mojang/minecraft/item/a.class
Writing com/mojang/minecraft/item/Arrow.class
Writing com/mojang/minecraft/item/Item.class
Writing com/mojang/minecraft/item/PrimedTnt.class
Writing com/mojang/minecraft/item/TakeEntityAnim.class
Writing com/mojang/minecraft/j.class
Writing com/mojang/minecraft/k.class
Writing com/mojang/minecraft/l.class
Writing com/mojang/minecraft/level/a/a/a.class
Writing com/mojang/minecraft/level/a/a/b.class
Writing com/mojang/minecraft/level/a/a/c.class
Writing com/mojang/minecraft/level/a/a/d.class
Writing com/mojang/minecraft/level/a/a.class
Writing com/mojang/minecraft/level/a.class
Writing com/mojang/minecraft/level/b/a.class
Writing com/mojang/minecraft/level/b.class
Writing com/mojang/minecraft/level/BlockMap$Slot.class
Writing com/mojang/minecraft/level/BlockMap.class
Writing com/mojang/minecraft/level/c.class
Writing com/mojang/minecraft/level/d.class
Writing com/mojang/minecraft/level/e.class
Writing com/mojang/minecraft/level/Level.class
Writing com/mojang/minecraft/level/tile/a.class
Writing com/mojang/minecraft/level/tile/b.class
Writing com/mojang/minecraft/level/tile/c.class
Writing com/mojang/minecraft/level/tile/d.class
Writing com/mojang/minecraft/level/tile/e.class
Writing com/mojang/minecraft/level/tile/f.class
Writing com/mojang/minecraft/level/tile/g.class
Writing com/mojang/minecraft/level/tile/h.class
Writing com/mojang/minecraft/level/tile/i.class
Writing com/mojang/minecraft/level/tile/j.class
Writing com/mojang/minecraft/level/tile/k.class
Writing com/mojang/minecraft/level/tile/l.class
Writing com/mojang/minecraft/level/tile/m.class
Writing com/mojang/minecraft/level/tile/n.class
Writing com/mojang/minecraft/level/tile/o.class
Writing com/mojang/minecraft/level/tile/p.class
Writing com/mojang/minecraft/level/tile/q.class
Writing com/mojang/minecraft/level/tile/r.class
Writing com/mojang/minecraft/level/tile/s.class
Writing com/mojang/minecraft/level/tile/t.class
Writing com/mojang/minecraft/level/tile/Tile$SoundType.class
Writing com/mojang/minecraft/Minecraft$OS.class
Writing com/mojang/minecraft/MinecraftApplet$1.class
Writing com/mojang/minecraft/MinecraftApplet.class
Writing com/mojang/minecraft/mob/ai/AI.class
Writing com/mojang/minecraft/mob/ai/BasicAI.class
Writing com/mojang/minecraft/mob/ai/BasicAttackAI.class
Writing com/mojang/minecraft/mob/ai/JumpAttackAI.class
Writing com/mojang/minecraft/mob/Creeper$1.class
Writing com/mojang/minecraft/mob/Creeper.class
Writing com/mojang/minecraft/mob/HumanoidMob.class
Writing com/mojang/minecraft/mob/Mob.class
Writing com/mojang/minecraft/mob/Pig.class
Writing com/mojang/minecraft/mob/QuadrupedMob.class
Writing com/mojang/minecraft/mob/Sheep$1.class
Writing com/mojang/minecraft/mob/Sheep.class
Writing com/mojang/minecraft/mob/Skeleton$1.class
Writing com/mojang/minecraft/mob/Skeleton.class
Writing com/mojang/minecraft/mob/Spider.class
Writing com/mojang/minecraft/mob/Zombie.class
Writing com/mojang/minecraft/net/a.class
Writing com/mojang/minecraft/net/b.class
Writing com/mojang/minecraft/net/c.class
Writing com/mojang/minecraft/net/d.class
Writing com/mojang/minecraft/net/e.class
Writing com/mojang/minecraft/net/NetworkPlayer.class
Writing com/mojang/minecraft/particle/a.class
Writing com/mojang/minecraft/particle/Particle.class
Writing com/mojang/minecraft/particle/SmokeParticle.class
Writing com/mojang/minecraft/particle/TerrainParticle.class
Writing com/mojang/minecraft/particle/WaterDropParticle.class
Writing com/mojang/minecraft/phys/AABB.class
Writing com/mojang/minecraft/player/a.class
Writing com/mojang/minecraft/player/b.class
Writing com/mojang/minecraft/player/Inventory.class
Writing com/mojang/minecraft/player/Player$1.class
Writing com/mojang/minecraft/player/Player.class
Writing com/mojang/minecraft/StopGameException.class
Writing de/jarnbjo/a/a/a.class
Writing de/jarnbjo/a/a/b.class
Writing de/jarnbjo/ogg/a.class
Writing de/jarnbjo/ogg/b.class
Writing de/jarnbjo/ogg/c.class
Writing de/jarnbjo/ogg/EndOfOggStreamException.class
Writing de/jarnbjo/ogg/OggFormatException.class
Writing de/jarnbjo/vorbis/a.class
Writing de/jarnbjo/vorbis/b.class
Writing de/jarnbjo/vorbis/c.class
Writing de/jarnbjo/vorbis/d.class
Writing de/jarnbjo/vorbis/e.class
Writing de/jarnbjo/vorbis/f.class
Writing de/jarnbjo/vorbis/g.class
Writing de/jarnbjo/vorbis/h.class
Writing de/jarnbjo/vorbis/i.class
Writing de/jarnbjo/vorbis/j.class
Writing de/jarnbjo/vorbis/k.class
Writing de/jarnbjo/vorbis/l.class
Writing de/jarnbjo/vorbis/m.class
Writing de/jarnbjo/vorbis/n.class
Writing de/jarnbjo/vorbis/o.class
Writing de/jarnbjo/vorbis/p.class
Writing de/jarnbjo/vorbis/q.class
Writing de/jarnbjo/vorbis/r.class
Writing de/jarnbjo/vorbis/VorbisFormatException.class
Writing default.gif
Writing default.png
Writing dirt.png
Writing grass.png
Writing gui/gui.png
Writing gui/icons.png
Writing item/arrows.png
Writing item/sign.png
Writing mob/creeper.png
Writing mob/pig.png
Writing mob/sheep.png
Writing mob/sheep_fur.png
Writing mob/skeleton.png
Writing mob/spider.png
Writing mob/zombie.png
Writing null
Writing particles.png
Writing rain.png
Writing rock.png
Writing terrain.png
Writing water.png
Constructor for World of Minecraft : java.net.URLClassLoader@ba6c83
java.util.ConcurrentModificationException
        at java.util.LinkedList$ListItr.checkForComodification(Unknown Source)
        at java.util.LinkedList$ListItr.next(Unknown Source)
        at com.World of Minecraft.CookieList.get(CookieList.java:33)
        at sun.net.www.protocol.http.HttpURLConnection.setCookieHeader(Unknown S
ource)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown So
urce)
        at com.World of Minecraft.ServerDialog.fetchUrl(ServerDialog.java:608)
        at com.World of Minecraft.ServerDialog.validateLogin(ServerDialog.java:679)
        at com.World of Minecraft.ServerDialog.<init>(ServerDialog.java:107)
        at com.World of Minecraft.Wom.run(World of Minecraft.java:264)
        at com.World of Minecraft.Boot.main(Boot.java:160)

C:\Users\Paul\Desktop\WoMTest\WoMClient-1.9.0>

Any help in resolving this problem would be appreciated.