http://pastebin.com/BVxZDqtd
http://pastebin.com/3cm3uXE2

2014-03-07 19:03:25 [SEVERE] [ForgeModLoader] An Entity type co.uk.flansmods.common.guns.EntityGrenade at world,-942.384705,72.000000,-3605.000000 has thrown an exception trying to write state. It will not persist. Report this to the mod author
net.minecraft.util.ReportedException: Saving entity NBT
at net.minecraft.entity.Entity.func_70109_d(Entity.java:1827)
at net.minecraft.entity.Entity.func_70039_c(Entity.java:1748)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75820_a(AnvilChunkLoader.java:397)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:215)
at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:371)
at net.minecraft.world.gen.ChunkProviderServer.func_73151_a(ChunkProviderServer.java:447)
at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:1263)
at org.bukkit.craftbukkit.v1_6_R3.CraftWorld.save(CraftWorld.java:716)
at org.bukkit.command.defaults.SaveCommand.execute(SaveCommand.java:30)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:192)
at org.bukkit.craftbukkit.v1_6_R3.CraftServer.dispatchCommand(CraftServer.java:533)
at org.bukkit.craftbukkit.v1_6_R3.CraftServer.dispatchServerCommand(CraftServer.java:514)
at net.minecraft.server.dedicated.DedicatedServer.func_71333_ah(DedicatedServer.java:374)
at net.minecraft.server.dedicated.DedicatedServer.func_71228_a(DedicatedServer.java:296)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:703)
at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)
Caused by: java.lang.NullPointerException
at co.uk.flansmods.common.guns.EntityGrenade.func_70014_b(EntityGrenade.java:404)
at net.minecraft.entity.Entity.func_70109_d(Entity.java:1810)
... 15 more