[01:57:27] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.util.ReportedException: Ticking GridNode
        at appeng.me.cache.TickManagerCache.onUpdateTick(TickManagerCache.java:107) ~[TickManagerCache.class:?]
        at appeng.me.GridCacheWrapper.onUpdateTick(GridCacheWrapper.java:22) ~[GridCacheWrapper.class:?]
        at appeng.me.Grid.update(Grid.java:208) ~[Grid.class:?]
        at appeng.hooks.TickHandler.onTick(TickHandler.java:244) ~[TickHandler.class:?]
        at cpw.mods.fml.common.eventhandler.ASMEventHandler_317_TickHandler_onTick_TickEvent.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:139) ~[EventBus.class:?]
        at cpw.mods.fml.common.FMLCommonHandler.onPostServerTick(FMLCommonHandler.java:247) ~[FMLCommonHandler.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:590) ~[MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
Caused by: java.util.ConcurrentModificationException
        at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1115) ~[?:1.7.0_67]
        at java.util.TreeMap$ValueIterator.next(TreeMap.java:1160) ~[?:1.7.0_67]
        at appeng.util.item.MeaningfulIterator.hasNext(MeaningfulIterator.java:23) ~[MeaningfulIterator.class:?]
        at appeng.crafting.MECraftingInventory.<init>(MECraftingInventory.java:92) ~[MECraftingInventory.class:?]
        at appeng.crafting.CraftingJob.<init>(CraftingJob.java:81) ~[CraftingJob.class:?]
        at appeng.me.cache.CraftingGridCache.beginCraftingJob(CraftingGridCache.java:598) ~[CraftingGridCache.class:?]
        at appeng.helpers.MultiCraftingTracker.handleCrafting(MultiCraftingTracker.java:98) ~[MultiCraftingTracker.class:?]
        at appeng.parts.automation.PartExportBus.doBusWork(PartExportBus.java:197) ~[PartExportBus.class:?]
        at appeng.parts.automation.PartExportBus.tickingRequest(PartExportBus.java:303) ~[PartExportBus.class:?]
        at appeng.me.cache.TickManagerCache.onUpdateTick(TickManagerCache.java:70) ~[TickManagerCache.class:?]
        ... 10 more
[01:57:27] [Server thread/ERROR]: This crash report has been saved to: /home/minecraft/minecraft/./crash-reports/crash-2014-10-09_01.57.27-server.txt