Often Recurring Severe and Unknown Bukkit Error

I have had this recurring problem on my server, that doesn't seem to affect anything but just keeps happening. It happens when the server starts up, and also in the middle of the game.

This is an emergency! Please help! The server ip is colbycraft.no-ip.org
I use bukkit GUI.

Here is the error with startup:
http://pastebin.com/embed_js.php?i=KxY5Qw0h

Code:

http://pastebin.com/embed_js.php?i=KxY5Qw0h

Here is my permissions file (very long... inheritance never worked...sorry!)
http://pastebin.com/embed_js.php?i=6h4yiUgM

Here are my plugins:
AutoAnnouncer
BKcommonLIb
ChatManager
ChestRestock
CoreProtect
CraftProxyLiter
EntityManager
Essentials
EssentialsSpawn
Factions
iBlock
IConomy
JSONAPI
LazyRoad
MinecraftRKitPlugin
MobDisguise
Modifyworld
NoCheat
NoLagg
NukeNow
PermissionsEx
RemoteBukkitPlugin
SetRankPEX
SignLift
SpamGuard
VanishNoPacket
Vault
WorldEdit
WorldGuard
WorldSaver

Please help!

 

Do you have the latest version of NoLagg and BKcommonLIb? If you don't, try updating them and seeing if the error occurs then.

 

Okay! I solved it. Nolagg was out of date. Thanks! Now do you know what it means when it says file not found exception in the console report i previously sent? ^