a.rb

[18:04:14] [Server thread/ERROR] [FML/]: A TileEntity type com.fireball1725.graves.tileentity.TileEntityGraveStone has throw an exception trying to writ\
e state. It will not persist. Report this to the mod author
java.lang.NullPointerException
        at net.minecraft.nbt.NBTUtil.func_180708_a(SourceFile:60) ~[dy.class:?]
        at com.fireball1725.graves.tileentity.TileEntityGraveStone.func_145841_b(TileEntityGraveStone.java:87) ~[TileEntityGraveStone.class:?]
        at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75820_a(AnvilChunkLoader.java:368) [anj.class:?]
        at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:165) [anj.class:?]
        at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:238) [ld.class:?]
        at net.minecraft.world.gen.ChunkProviderServer.func_73151_a(ChunkProviderServer.java:298) [ld.class:?]
        at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:904) [le.class:?]
        at net.minecraft.server.MinecraftServer.func_71267_a(MinecraftServer.java:366) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.func_71260_j(MinecraftServer.java:398) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:534) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_66]
[18:04:14] [Server thread/INFO] [THAUMCRAFT/]: Removing aura cache for world 0