[00:45:36] [Server thread/ERROR] [FML]: Exception caught during firing event net.minecraftforge.event.world.BlockEvent$HarvestDropsEvent@94d3302:
java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:859) ~[?:1.7.0_79]
        at java.util.ArrayList$Itr.next(ArrayList.java:831) ~[?:1.7.0_79]
        at tterrag.core.common.handlers.AutoSmeltHandler.handleBlockBreak(AutoSmeltHandler.java:34) ~[AutoSmeltHandler.class:?]
        at cpw.mods.fml.common.eventhandler.ASMEventHandler_795_AutoSmeltHandler_handleBlockBreak_HarvestDropsEvent.invoke(.dynamic) ~[?:?]
        at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:54) ~[ASMEventHandler.class:?]
        at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:138) [EventBus.class:?]
        at net.minecraftforge.event.ForgeEventFactory.fireBlockHarvesting(ForgeEventFactory.java:155) [ForgeEventFactory.class:?]
        at net.minecraft.block.Block.func_149690_a(Block.java:656) [aji.class:?]
        at net.minecraft.block.BlockRedstoneOre.func_149690_a(BlockRedstoneOre.java:91) [amz.class:?]
        at net.minecraft.block.Block.func_149697_b(Block.java:648) [aji.class:?]
        at net.minecraft.block.Block.func_149636_a(Block.java:974) [aji.class:?]
        at net.minecraft.server.management.ItemInWorldManager.func_73084_b(ItemInWorldManager.java:299) [mx.class:?]
        at net.minecraft.server.management.ItemInWorldManager.func_73082_a(ItemInWorldManager.java:217) [mx.class:?]
        at net.minecraft.network.NetHandlerPlayServer.func_147345_a(NetHandlerPlayServer.java:498) [nh.class:?]
        at net.minecraft.network.play.client.C07PacketPlayerDigging.func_148833_a(SourceFile:53) [ji.class:?]
        at net.minecraft.network.play.client.C07PacketPlayerDigging.func_148833_a(SourceFile:8) [ji.class:?]
        at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212) [ej.class:?]
        at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:165) [nc.class:?]
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:659) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:334) [lt.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]