java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_121]
	at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_121]
	at net.minecraft.util.Util.runTask(Util.java:30) [Util.class:?]
	at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:754) [MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:699) [MinecraftServer.class:?]
	at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156) [IntegratedServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:548) [MinecraftServer.class:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.lang.NullPointerException
	at net.minecraft.inventory.Slot.getStack(Slot.java:81) ~[Slot.class:?]
	at net.minecraft.inventory.Container.getInventory(Container.java:71) ~[Container.class:?]
	at net.minecraft.inventory.Container.addListener(Container.java:57) ~[Container.class:?]
	at com.bubbletrouble.gunmod.common.container.ContainerCrafter.addListener(ContainerCrafter.java:72) ~[ContainerCrafter.class:?]
	at net.minecraftforge.fml.common.network.internal.FMLNetworkHandler.openGui(FMLNetworkHandler.java:102) ~[FMLNetworkHandler.class:?]
	at net.minecraft.entity.player.EntityPlayer.openGui(EntityPlayer.java:2739) ~[EntityPlayer.class:?]
	at com.bubbletrouble.gunmod.common.block.BlockCrafter.onBlockActivated(BlockCrafter.java:74) ~[BlockCrafter.class:?]
	at net.minecraft.server.management.PlayerInteractionManager.processRightClickBlock(PlayerInteractionManager.java:474) ~[PlayerInteractionManager.class:?]
	at net.minecraft.network.NetHandlerPlayServer.processTryUseItemOnBlock(NetHandlerPlayServer.java:713) ~[NetHandlerPlayServer.class:?]
	at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.processPacket(CPacketPlayerTryUseItemOnBlock.java:68) ~[CPacketPlayerTryUseItemOnBlock.class:?]
	at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.processPacket(CPacketPlayerTryUseItemOnBlock.java:13) ~[CPacketPlayerTryUseItemOnBlock.class:?]
	at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:21) ~[PacketThreadUtil$1.class:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_121]
	at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_121]
	at net.minecraft.util.Util.runTask(Util.java:29) ~[Util.class:?]
	... 5 more
[13:29:46] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.util.ReportedException: Ticking player
	at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:801) ~[MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:699) ~[MinecraftServer.class:?]
	at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156) ~[IntegratedServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:548) [MinecraftServer.class:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.lang.NullPointerException
	at net.minecraft.inventory.Slot.getStack(Slot.java:81) ~[Slot.class:?]
	at net.minecraft.inventory.Container.detectAndSendChanges(Container.java:93) ~[Container.class:?]
	at com.bubbletrouble.gunmod.common.container.ContainerCrafter.detectAndSendChanges(ContainerCrafter.java:161) ~[ContainerCrafter.class:?]
	at net.minecraft.entity.player.EntityPlayerMP.onUpdate(EntityPlayerMP.java:319) ~[EntityPlayerMP.class:?]
	at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2122) ~[World.class:?]
	at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:883) ~[WorldServer.class:?]
	at net.minecraft.world.World.updateEntity(World.java:2089) ~[World.class:?]
	at net.minecraft.world.WorldServer.tickPlayers(WorldServer.java:680) ~[WorldServer.class:?]
	at net.minecraft.world.World.updateEntities(World.java:1878) ~[World.class:?]
	at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:651) ~[WorldServer.class:?]
	at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:795) ~[MinecraftServer.class:?]
	... 4 more