Crash error

Out of know where the server crashes and i get:

17:46:59 [SEVERE] java.util.ConcurrentModificationException
17:46:59 [SEVERE] at java.util.AbstractList$Itr.checkForComodification(Unk
nown Source)
17:46:59 [SEVERE] at java.util.AbstractList$Itr.next(Unknown Source)
17:46:59 [SEVERE] at java.util.AbstractCollection.removeAll(Unknown Source
)
17:46:59 [SEVERE] at net.minecraft.server.World.tickEntities(World.java:11
13)
17:46:59 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServe
r.java:525)
17:46:59 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftSer
ver.java:432)
17:46:59 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(Sour
ceFile:465)
17:46:59 [SEVERE] Unexpected exception
java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
at java.util.AbstractList$Itr.next(Unknown Source)
at java.util.AbstractCollection.removeAll(Unknown Source)
at net.minecraft.server.World.tickEntities(World.java:1113)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:525)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:432)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)
17:46:59 [INFO] [bPermissions - debug] Setup player:markuskolind took 66ms
17:47:13 [INFO] Connection reset
17:48:06 [INFO] Read timed out
17:48:10 [INFO] Read timed out

Anyone knows what this is related to?

 

The important lines are cut off

 

http://goo.gl/mU3Y9

More lines added here​

 

Anyone
btw
bukkit - 1717

 

Hmm, what plugins are you using?

 

I understand that this thread is a little bit dead, by the server i am an administrator on recently ran into a problem similar to this. While we did not get this error often, it did appear, from the research i did, that it could be caused by any outdated plugins. While this was not our problem fully, we did get that error, and updating them seemed to fix it. Our problem was some corrupted chunks caused us to go down whenever someone was near it. This caused the error to come out a few times. I recommend updating your plugins, and also checking to see if there are any corrupt chunks anywhere on your map. This is an annoying problem, yes, but it can be fixed.