Bukkit

2012-10-01 19:00:02 [SEVERE] Exception in thread "pool-1-thread-54"
2012-10-01 19:00:02 [SEVERE] org.apache.commons.lang.UnhandledException: Plugin VirtualChest v5.6.5 generated an exception while executing task 26
    at org.bukkit.craftbukkit.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.util.ConcurrentModificationException
    at java.util.HashMap$HashIterator.nextEntry(HashMap.java:848)
    at java.util.HashMap$KeyIterator.next(HashMap.java:883)
    at com.zone.vchest.utils.FilesManager.savePerPlayer(FilesManager.java:135)
    at com.zone.vchest.VirtualChestWorker.save(VirtualChestWorker.java:459)
    at com.zone.vchest.VirtualChestPlugin$1.run(VirtualChestPlugin.java:221)
    at org.bukkit.craftbukkit.scheduler.CraftTask.run(CraftTask.java:52)
    at org.bukkit.craftbukkit.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
    ... 3 more

What is the expected output? What do you see instead?

What version of the product are you using? Newest one

Do you have an error log of what happened?

Please provide any additional information below. I just updated spamguard to the newest version, could it SpamGuard fault?

I removed spamguard, still getting crashed on RB, may you fix it?