[15:19:21] [Server thread/ERROR] [FML]: A TileEntity type exokem.exkva.objects.machines.TileEntityPassiveCollector has throw an exception trying to write state. It will not persist. Report this to the mod author
java.lang.NullPointerException: null
	at exokem.exkva.objects.machines.TileEntityMachineBase.writeToNBT(TileEntityMachineBase.java:115) ~[TileEntityMachineBase.class:?]
	at net.minecraft.world.chunk.storage.AnvilChunkLoader.writeChunkToNBT(AnvilChunkLoader.java:414) [AnvilChunkLoader.class:?]
	at net.minecraft.world.chunk.storage.AnvilChunkLoader.saveChunk(AnvilChunkLoader.java:185) [AnvilChunkLoader.class:?]
	at net.minecraft.world.gen.ChunkProviderServer.saveChunkData(ChunkProviderServer.java:214) [ChunkProviderServer.class:?]
	at net.minecraft.world.gen.ChunkProviderServer.saveChunks(ChunkProviderServer.java:242) [ChunkProviderServer.class:?]
	at net.minecraft.world.WorldServer.saveAllChunks(WorldServer.java:1061) [WorldServer.class:?]
	at net.minecraft.server.MinecraftServer.saveAllWorlds(MinecraftServer.java:468) [MinecraftServer.class:?]
	at net.minecraft.server.integrated.IntegratedServer.saveAllWorlds(IntegratedServer.java:274) [IntegratedServer.class:?]
	at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:177) [IntegratedServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:592) [MinecraftServer.class:?]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]

@Override
    public NBTTagCompound writeToNBT(NBTTagCompound compound) {
        compound = super.writeToNBT(compound);
        compound.setTag("inventory", inventory.serializeNBT());
        compound.setInteger("active_time", activeTime);
        compound.setBoolean("active", active);
        if(hasEnergy) {
            compound.setInteger("stored_energy", energyStorage.getEnergyStored());
        }
        return compound;
    }