[Server thread/FATAL] [minecraft/MinecraftServer]: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
        at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_45]
        at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_45]
        at net.minecraft.util.Util.func_181617_a(SourceFile:47) [h.class:?]
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:723) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397) [nz.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526) [MinecraftServer.class:?]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_45]
Caused by: java.lang.NullPointerException
        at net.minecraft.inventory.ItemStackHelper.func_191281_a(SourceFile:34) ~[tw.class:?]
        at net.minecraft.inventory.ItemStackHelper.func_191282_a(SourceFile:29) ~[tw.class:?]
        at micdoodle8.mods.galacticraft.core.tile.TileEntityInventory.func_189515_b(TileEntityInventory.java:77) ~[TileEntityInventory.class:?]
        at micdoodle8.mods.galacticraft.core.energy.tile.EnergyStorageTile.func_189515_b(EnergyStorageTile.java:41) ~[EnergyStorageTile.class:?]
        at micdoodle8.mods.galacticraft.core.energy.tile.TileBaseUniversalElectrical.func_189515_b(TileBaseUniversalElectrical.java:184) ~[TileBaseUniversalElectrical.class:?]
        at micdoodle8.mods.galacticraft.core.tile.TileEntityCoalGenerator.func_189515_b(TileEntityCoalGenerator.java:118) ~[TileEntityCoalGenerator.class:?]
        at net.minecraftforge.common.util.BlockSnapshot.getTileNBT(BlockSnapshot.java:132) ~[BlockSnapshot.class:?]
        at net.minecraftforge.common.util.BlockSnapshot.<init>(BlockSnapshot.java:61) ~[BlockSnapshot.class:?]
        at net.minecraftforge.common.util.BlockSnapshot.<init>(BlockSnapshot.java:82) ~[BlockSnapshot.class:?]
        at net.minecraftforge.common.util.BlockSnapshot.getBlockSnapshot(BlockSnapshot.java:113) ~[BlockSnapshot.class:?]
        at net.minecraft.world.World.func_180501_a(World.java:336) ~[amu.class:?]
        at micdoodle8.mods.galacticraft.core.blocks.BlockMachine.func_180633_a(BlockMachine.java:138) ~[BlockMachine.class:?]
        at net.minecraft.item.ItemBlock.placeBlockAt(ItemBlock.java:186) ~[ahb.class:?]
        at net.minecraft.item.ItemBlock.func_180614_a(ItemBlock.java:54) ~[ahb.class:?]
        at net.minecraftforge.common.ForgeHooks.onPlaceItemIntoWorld(ForgeHooks.java:889) ~[ForgeHooks.class:?]
        at net.minecraft.item.ItemStack.func_179546_a(ItemStack.java:186) ~[aip.class:?]
        at net.minecraft.server.management.PlayerInteractionManager.func_187251_a(PlayerInteractionManager.java:481) ~[or.class:?]
        at net.minecraft.network.NetHandlerPlayServer.func_184337_a(NetHandlerPlayServer.java:741) ~[pa.class:?]
        at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.func_148833_a(SourceFile:55) ~[ma.class:?]
        at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.func_148833_a(SourceFile:11) ~[ma.class:?]
        at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) ~[hv$1.class:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_45]
        at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_45]
        at net.minecraft.util.Util.func_181617_a(SourceFile:46) ~[h.class:?]
        ... 5 more