Fatal Error in console

 [Fatal] Error executing taskjava.util.concurrent.ExecutionException: java.lang.NullPointerException	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_102]	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_102]	at net.minecraft.util.Util.func_181617_a(SourceFile:46) [h.class:?]	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:668) [MinecraftServer.class:?]	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:387) [ld.class:?]	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:613) [MinecraftServer.class:?]	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:471) [MinecraftServer.class:?]	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_102]Caused by: java.lang.NullPointerException	at exnihiloadscensio.barrel.modes.compost.BarrelModeCompost.onBlockActivated(BarrelModeCompost.java:81) ~[BarrelModeCompost.class:?]	at exnihiloadscensio.tiles.TileBarrel.onBlockActivated(TileBarrel.java:125) ~[TileBarrel.class:?] at exnihiloadscensio.blocks.BlockBarrel.func_180639_a(BlockBarrel.java:126) ~[BlockBarrel.class:?]	at net.minecraft.server.management.PlayerInteractionManager.func_187251_a(PlayerInteractionManager.java:451) ~[lv.class:?]	at net.minecraft.network.NetHandlerPlayServer.func_184337_a(NetHandlerPlayServer.java:679) ~[me.class:?]	at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.func_148833_a(SourceFile:55) ~[jj.class:?]	at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.func_148833_a(SourceFile:11) ~[jj.class:?]	at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) ~[fl$1.class:?]	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_102]	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_102]	at net.minecraft.util.Util.func_181617_a(SourceFile:45) ~[h.class:?]	... 5 more