2013-10-27 22:12:14 [SEVERE] java.util.ConcurrentModificationException
2013-10-27 22:12:14 [SEVERE] 	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:839)
2013-10-27 22:12:14 [SEVERE] 	at java.util.HashMap$ValueIterator.next(HashMap.java:868)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75820_a(AnvilChunkLoader.java:420)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:215)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:336)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.gen.ChunkProviderServer.func_73151_a(ChunkProviderServer.java:413)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:1251)
2013-10-27 22:12:14 [SEVERE] 	at org.bukkit.craftbukkit.v1_6_R3.CraftWorld.save(CraftWorld.java:653)
2013-10-27 22:12:14 [SEVERE] 	at com.wimbli.WorldBorder.WorldFillTask.reportProgress(WorldFillTask.java:394)
2013-10-27 22:12:14 [SEVERE] 	at com.wimbli.WorldBorder.WorldFillTask.run(WorldFillTask.java:168)
2013-10-27 22:12:14 [SEVERE] 	at org.bukkit.craftbukkit.v1_6_R3.scheduler.CraftTask.run(CraftTask.java:67)
2013-10-27 22:12:14 [SEVERE] 	at org.bukkit.craftbukkit.v1_6_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:810)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:327)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:765)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:647)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)
2013-10-27 22:12:14 [SEVERE] java.util.ConcurrentModificationException
2013-10-27 22:12:14 [SEVERE] 	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:839)
2013-10-27 22:12:14 [SEVERE] 	at java.util.HashMap$ValueIterator.next(HashMap.java:868)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75820_a(AnvilChunkLoader.java:420)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:215)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:336)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.gen.ChunkProviderServer.func_73151_a(ChunkProviderServer.java:413)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:1251)
2013-10-27 22:12:14 [SEVERE] 	at org.bukkit.craftbukkit.v1_6_R3.CraftWorld.save(CraftWorld.java:653)
2013-10-27 22:12:14 [SEVERE] 	at com.wimbli.WorldBorder.WorldFillTask.reportProgress(WorldFillTask.java:394)
2013-10-27 22:12:14 [SEVERE] 	at com.wimbli.WorldBorder.WorldFillTask.run(WorldFillTask.java:168)
2013-10-27 22:12:14 [SEVERE] 	at org.bukkit.craftbukkit.v1_6_R3.scheduler.CraftTask.run(CraftTask.java:67)
2013-10-27 22:12:14 [SEVERE] 	at org.bukkit.craftbukkit.v1_6_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:810)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:327)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:765)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:647)
2013-10-27 22:12:14 [SEVERE] 	at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)