java.lang.NullPointerException: Exception in server tick loop
        at appeng.helpers.DualityInterface.invIsBlockedGTCE(DualityInterface.java:1045)
        at appeng.helpers.DualityInterface.isGTCEblocked(DualityInterface.java:1217)
        at appeng.helpers.DualityInterface.isBusy(DualityInterface.java:1195)
        at appeng.me.cluster.implementations.CraftingCPUCluster.executeCrafting(CraftingCPUCluster.java:659)
        at appeng.me.cluster.implementations.CraftingCPUCluster.updateCraftingLogic(CraftingCPUCluster.java:610)
        at appeng.me.cache.CraftingGridCache.onUpdateTick(CraftingGridCache.java:154)
        at appeng.me.GridCacheWrapper.onUpdateTick(GridCacheWrapper.java:43)
        at appeng.me.Grid.update(Grid.java:284)
        at appeng.hooks.TickHandler.onTick(TickHandler.java:227)
        at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_1118_TickHandler_onTick_TickEvent.invoke(.dynamic)
        at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
        at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
        at net.minecraftforge.fml.common.FMLCommonHandler.onPostServerTick(FMLCommonHandler.java:266)
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:712)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
        at java.lang.Thread.run(Thread.java:748)