Server Crashes upon player entry

[BrandonBP]

My server had been running very smoothly and suddenly crashed. Now, whenever anyone logs in it freezes then crashes again. I'd really appreciate any help

http://pastebin.com/4LEJ68mA

1. ---- Minecraft Crash Report ----
2. // I blame Dinnerbone.
4. Time: 1/10/13 1:18 AM
5. Description: Exception in server tick loop
7. java.util.ConcurrentModificationException
8. at java.util.HashMap$HashIterator.nextEntry(HashMap.java:806)
9. at java.util.HashMap$KeyIterator.next(HashMap.java:841)
10. at hz.a(EntityTracker.java:202)
11. at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:653)
12. at hg.r(DedicatedServer.java:241)
13. at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:585)
14. at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:492)
15. at fp.run(SourceFile:818)
17. Relevant Details:
18. - Minecraft Version: 1.4.2
19. - Operating System: FreeBSD (amd64) version 8.3-RELEASE-p4
20. - Java Version: 1.7.0_04, Oracle Corporation
21. - Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
22. - Memory: 386688056 bytes (368 MB) / 1410453504 bytes (1345 MB) up to 2134114304 bytes (2035 MB)
23. - JVM Flags: 8 total; -Xmn128M -Xms160M -Xmx2048M -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XXarallelGCThreads=2 -XX:+AggressiveOpts
24. - AABB Pool Size: 13423 (751688 bytes; 0 MB) allocated, 9716 (544096 bytes; 0 MB) used
25. - FML: ~ERROR~ NullPointerException: null
26. - Is Modded: Definitely; 'forge,fml'
27. - Profiler Position: N/A (disabled)
28. - Vec3 Pool Size: 20205 (1131480 bytes; 1 MB) allocated, 13883 (777448 bytes; 0 MB) used
29. - Player Count: 4 / 12; [ih['FledgeChangeling'/781405, l='ftb', x=106.25, y=89.00, z=-6.28], ih['LM17'/1321779, l='ftb', x=354.78, y=62.16, z=12442.06], ih['Wawaa'/1389620, l='ftb', x=-450.92, y=62.95, z=-9722.44], ih['BrandonBP'/1395940, l='ftb', x=-242.75, y=66.00, z=-1492.61]]
30. - World ftb Entities: 0 total; []
31. - World ftb Players: 0 total; []
32. - World ftb Chunk Stats: ServerChunkCache: 0 Drop: 0
33. - Type: Dedicated Server

 

[Ashzification]

Try updating your Java.
It could be a corrupted player file/chunk. You could try resetting the player .dat files, but this will clear inventories and reset the players to the spawn point.

 

[BrandonBP]

It ended up being a BuildCraft bug with the filler. I have no idea what caused it, but that chunk the filler was in was the culprit. I had to rollback the server a few hours which, of course, always makes everyone very happy.

 

[Ashzification]

It's better than needing to wipe the map!

 

[Sim...]

What are you using for rollbacks if I may ask?

 

[BrandonBP]

What are you using for rollbacks if I may ask?

I'm using the saved worlds from the ClanForge console.