Help with error that crashes server

Sorry for bad English

Hi
I have a problem with error, that crashes my server every 30 minutes

15:21:21 [SEVERE] java.util.ConcurrentModificationException
15:21:21 [SEVERE] at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
15:21:21 [SEVERE] at java.util.AbstractList$Itr.next(AbstractList.java:343)
15:21:21 [SEVERE] at net.minecraft.server.World.tickEntities(World.java:1165)
15:21:21 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:518)
15:21:21 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:425)
15:21:21 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)
15:21:21 [SEVERE] Unexpected exception
java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
at java.util.AbstractList$Itr.next(AbstractList.java:343)
at net.minecraft.server.World.tickEntities(World.java:1165)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:518)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:425)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)
15:21:42 [INFO] Connection reset

My plugins: borderguard, buttonwarp, chestshop, commandbook, craftbook, Founddiamonds, iconomy,
Jobs, LWC, magiccarpet, memmonitor, Multiverse, OpenInv, PEX, SimpleRegionMarket, SpleefExtreme, Spout, Worldedit, Worldguard, xAuth
Bukkit version 1.0.1
I don't know what OS because its on hosting but probably linux.

I thought that was problem with backup plugins but i removed all and server still crashes.
Thank you

refresh

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

This fatal exception is caused by a poorly written plugin interfering with the main thread of the server. I know that it doesn't happen very often (usually) but I would recommend trying it without buttonwarp, borderguard, Founddiamonds, and memmonitor. You should also check the BukkitDev page for these plugins as you may be able to find others with the same exception.

 

Thanks, and sometimes i have this error

17:20:02 [SEVERE] Exception in thread "Thread-9515"
17:20:02 [SEVERE] java.lang.IllegalStateException: Failed to add player. net.minecraft.server.EntityPlayer@1a50b(Dawid44w at -212.0,64.0,169.0) already is in chunk -14, 10
17:20:02 [SEVERE] at net.minecraft.server.PlayerInstance.a(PlayerInstance.java:36)
17:20:02 [SEVERE] at net.minecraft.server.PlayerManager.addPlayer(PlayerManager.java:73)
17:20:02 [SEVERE] at net.minecraft.server.ServerConfigurationManager.moveToWorld(ServerConfigurationManager.java:287)
17:20:02 [SEVERE] at org.bukkit.craftbukkit.entity.CraftPlayer.teleport(CraftPlayer.java:316)
17:20:02 [SEVERE] at org.bukkit.craftbukkit.entity.CraftEntity.teleport(CraftEntity.java:156)
17:20:02 [SEVERE] at com.codisimus.plugins.buttonwarp.Warp$1.run(Warp.java:336)