java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:839)
	at java.util.HashMap$KeyIterator.next(HashMap.java:874)
	at java.util.AbstractCollection.addAll(AbstractCollection.java:333)
	at java.util.HashSet.<init>(HashSet.java:117)
	at mffs.tile.TileForceFieldProjector.projectField(TileForceFieldProjector.java:256)
	at mffs.tile.TileForceFieldProjector.func_70316_g(TileForceFieldProjector.java:181)
	at net.minecraft.world.World.func_72939_s(World.java:2717)
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:887)
	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:330)
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:781)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:663)
	at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)