Have you seen this crash?

[belgabor]

Hi everybody,

usually I'm quite good at determining the source of crashes I get, but this one has me stumped. I'm using dw20 on SSP with quite a couple of mods added, so I'm clearly beyond any official help.
First, without much further ado, the crash:

Spoiler

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 15.03.14 17:29
Description: Exception in world tick

java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
at java.util.HashMap$ValueIterator.next(Unknown Source)
at net.minecraft.world.chunk.Chunk.func_76607_a(Chunk.java:1465)
at net.minecraft.client.multiplayer.NetClientHandler.func_72463_a(NetClientHandler.java:775)
at net.minecraft.network.packet.Packet51MapChunk.func_73279_a(Packet51MapChunk.java:171)
at net.minecraft.network.MemoryConnection.func_74428_b(MemoryConnection.java:89)
at net.minecraft.client.multiplayer.NetClientHandler.func_72551_d(NetClientHandler.java:281)
at net.minecraft.client.multiplayer.WorldClient.func_72835_b(WorldClient.java:99)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1930)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:910)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:838)
at net.minecraft.client.main.Main.main(SourceFile:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

Full Log: http://pastebin.com/UQAMnu8t

Facts about it:

• Seems to be absolutely random, I couldn't determine any factor that causes it
• Increased in frequency over the last weeks. At first I had it at most once a week (and that was while I still played almost every day for a couple of hours). Now I'm at 3 to 4 times a day (if I don't frustration-quit before that), can happen immediately after I start up to after a few hours of playing.
• Internet gave me no help. The only thing I have seen are pastbins of it, so I'm not alone...
• The random nature of it makes it kinda hard to test by removing mods. Also many are now quite essential to my base up to the point where removing one would be pointless in determining the cause.
• It's not AM2, this is the one mod I removed to test whether it's responsible.

Basically I'm lost now, it's gone to the point where I'm so frustrated that I consider scrapping the world and starting over
Any help would be much appreciated, I'm aware that the log is basically free of any useful information. Probably only someone who as seen it an knows the reason can help, hence the title.

One more point of additional info, now and then I also get this crash. Frequency is much less though.

Spoiler

---- Minecraft Crash Report ----
// I just don't know what went wrong

Time: 13.03.14 15:31
Description: Exception in world tick

java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
at java.util.HashMap$ValueIterator.next(Unknown Source)
at net.minecraft.world.chunk.Chunk.func_76607_a(Chunk.java:1465)
at net.minecraft.client.multiplayer.NetClientHandler.func_72453_a(NetClientHandler.java:1432)
at net.minecraft.network.packet.Packet56MapChunks.func_73279_a(Packet56MapChunks.java:195)
at net.minecraft.network.MemoryConnection.func_74428_b(MemoryConnection.java:89)
at net.minecraft.client.multiplayer.NetClientHandler.func_72551_d(NetClientHandler.java:281)
at net.minecraft.client.multiplayer.WorldClient.func_72835_b(WorldClient.java:99)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1930)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:910)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:838)
at net.minecraft.client.main.Main.main(SourceFile:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

 

[rhn]

1: this belongs in the new support site, not here.
2: The short cutout of the crash report is of little to no help. Post the whole log to pastebin and link it here(or actually on the new support site to be correct).

 

[belgabor]

1. I don't think issues using a mod pack with > 10 mods added should go onto the official support site, neither do I think the team would appreciate that.
2. In this specific case I'm pretty sure that won't help but I'll add one to the OP.

 

[Pokefenn]

Had a quick glance, I think its the hats mod crash.
It corrupts the Level.dat

 

[belgabor]

Had a quick glance, I think its the hats mod crash.
It corrupts the Level.dat

So this effs me up even after I take hats out? I took it out after some more specific crashes a while ago, but that was after I starting getting this crash.

 

[belgabor]

For the record.
Got sick of the issue, so I made a new world with a modpack based on Monster (added a couple of mods). Worked fine for a good while when I started to get the issue again. At that point I was getting really frustrated (and I could tell with certainty that it's not hats, that one never touched this world). I again did some research which now yielded two plausible hints. Unfortunately neither sported a "That was it!" final response.

One thread suggested a corrupted entity, so I killed off everything in reach (yay cofh!). Got the crash again, so no dice.

The other one suggested that it's Zan's Minimap/Voxelmap. Removed it and no crash since (well, no this one at least...). Due to the random nature I cannot be 100% sure, but I've played for hours now without a reoccurence.
Unfortunately I can't find the thread anymore, so I cannot give proper credit to whoever pointed that out, but whoever it was, thanks a lot!