Minecraft Forums

So I was playing arond with SPC's cannon command until I got this:
Minecraft has stopped running because it encountered a problem; Exception in server tick loop
This error has been saved to C:\Users\Joey\AppData\Roaming\.minecraft\crash-reports\crash-2012-09-22_19.54.45-server.txt for your convenience. Please include a copy of this file if you report this crash to anyone.



--- BEGIN ERROR REPORT 16dd65e4 --------
Generated 9/22/12 7:54 PM

- Minecraft Version: 1.3.2
- Operating System: Windows Vista (x86) version 6.0
- Java Version: 1.7.0_07, Oracle Corporation
- Java VM Version: Java HotSpot™ Client VM (mixed mode), Oracle Corporation
- Memory: 217386152 bytes (207 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
- JVM Flags: 2 total; -Xms512m -Xmx1024m
- FML: FML v3.0.165.344 Minecraft Forge 4.0.0.241 Optifine OptiFine_1.3.2_HD_U_B3 11 mods loaded, 11 mods active
FML [Forge Mod Loader] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
Forge [Minecraft Forge] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_ElementalCreepers [mod_ElementalCreepers] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_FriendsOverlay [mod_FriendsOverlay] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_GoodMobs [mod_GoodMobs] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_ModLoaderMp [mod_ModLoaderMp] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_TooManyItems [mod_TooManyItems] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
jfm [JammyFurniture] (1.3.2_Jammy_Furniture_Mod_Universal_BETA_V4.2.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_ReiMinimap [mod_ReiMinimap] ([1.3.2]ReiMinimap_v3.2_05.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
CustomNpcs [Custom Npcs] (customnpcs 1.3.2 v0.7.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
mod_HDSkins [mod_HDSkins] (mod_HDSkins.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available->Available->Available->Available->Available
- Is Modded: Definitely; 'forge,fml'
- Profiler Position: N/A (disabled)
- Player Count: 1 / 8; [gu['ChildLink'/5531168, l='Flatbox', x=2894.07, y=4.00, z=-141.90]]
- World Flatbox Entities: 0 total; []
- World Flatbox Players: 0 total; []
- World Flatbox Chunk Stats: ServerChunkCache: 0 Drop: 0
- Type: Integrated Server

java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
at java.util.HashMap$KeyIterator.next(Unknown Source)
at gm.a(EntityTracker.java:190)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:618)
at net.minecraft.server.MinecraftServer.p(MinecraftServer.java:547)
at axv.p(IntegratedServer.java:105)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:453)
at ep.run(SourceFile:539)
--- END ERROR REPORT 40b2777b ----------

Is this anything to be worried about?

Friends overlay says it needs to be updated.