Windows .jar Strange server log error spam [Mindcrack]

[bigougit]

I've been getting the same error in my server log and it seems to be showing up more frequently lately.

This is the error message that shows up:

2013-01-24 12:12:46 [INFO] [STDERR] java.util.ConcurrentModificationException
2013-01-24 12:12:46 [INFO] [STDERR]    at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
2013-01-24 12:12:46 [INFO] [STDERR]    at java.util.HashMap$ValueIterator.next(Unknown Source)
2013-01-24 12:12:46 [INFO] [STDERR]    at bq.a(SourceFile:24)
2013-01-24 12:12:46 [INFO] [STDERR]    at cd.a(SourceFile:114)
2013-01-24 12:12:46 [INFO] [STDERR]    at bq.a(SourceFile:25)
2013-01-24 12:12:46 [INFO] [STDERR]    at by.a(SourceFile:26)
2013-01-24 12:12:46 [INFO] [STDERR]    at cd.a(SourceFile:114)
2013-01-24 12:12:46 [INFO] [STDERR]    at bq.a(SourceFile:25)
2013-01-24 12:12:46 [INFO] [STDERR]    at cd.a(SourceFile:114)
2013-01-24 12:12:46 [INFO] [STDERR]    at bq.a(SourceFile:25)
2013-01-24 12:12:46 [INFO] [STDERR]    at cd.a(SourceFile:114)
2013-01-24 12:12:46 [INFO] [STDERR]    at ca.a(CompressedStreamTools.java:140)
2013-01-24 12:12:46 [INFO] [STDERR]    at aam.a(AnvilChunkLoader.java:198)
2013-01-24 12:12:46 [INFO] [STDERR]    at aam.c(AnvilChunkLoader.java:184)
2013-01-24 12:12:46 [INFO] [STDERR]    at aiw.b(SourceFile:29)
2013-01-24 12:12:46 [INFO] [STDERR]    at aiw.run(SourceFile:22)
2013-01-24 12:12:46 [INFO] [STDERR]    at java.lang.Thread.run(Unknown Source)

Here's a big chunk of the server log with the same message about a dozen times, with or without players present: http://pastebin.com/96B3FXiy
(the full log is too big for pastebin)

The error doesn't mention any mods specifically, so I'm at a loss. While I run the server from the same computer I play on, that's never been an issue before. I've given the server 2GB out of 16, and it runs off of a ramDisk.

Not sure if this will help, but this is whats happening when no one is on the server:
There are 3 chickenchunks chunk loaders (2 in overworld, 1 in nether) that run when no-one is on. One for ore processing with Thermal Expansion (items move using red power, stored in barrels). Another is for a turtle quarry, which sends items via enderchest. And the third is a pump in the nether to send lava containers to my main base via liquid transposers.

I'm assuming the issue is either with chunk loaders or something happening in those chunks since the error appears regardless of player activity. Fortunately this doesn't seem to cause any damage, but it is appearing more frequently.

Hopefully someone can shed light on the issue.

 

[Nessiroj]

I have seen alot off these errors lately no idea whats causing it, since we haven't found a solution / most ppl don't report back that it's solved.
Have you tried if removing the chunkloaders helps? did the same thing happen when you load the world in singleplayer?

 

[bigougit]

I'll do some more testing and report back.

 

[bigougit]

I may have found the issue. Looks like my lava pump was pulling lava from outside the chunk loaded area. After increasing the range of the chunkloader and haven't seen the error since.