Furnace error

---- Minecraft Crash Report ----
// Don't be sad, have a hug! <3

Time: 3/23/15 5:49 PM
Description: Ticking entity

java.lang.NullPointerException: Ticking entity
    at net.minecraft.inventory.Slot.getStack(Slot.java:79)
    at net.minecraft.inventory.Container.detectAndSendChanges(Container.java:97)
    at com.Hmod.container.ContainerFurnace.detectAndSendChanges(ContainerFurnace.java:158)
    at net.minecraft.entity.player.EntityPlayerMP.onUpdate(EntityPlayerMP.java:263)
    at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2016)
    at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:758)
    at net.minecraft.world.World.updateEntity(World.java:1982)
    at net.minecraft.world.World.updateEntities(World.java:1808)
    at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:587)
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:774)
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:669)
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:171)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:540)
    at java.lang.Thread.run(Unknown Source)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
    at net.minecraft.inventory.Slot.getStack(Slot.java:79)
    at net.minecraft.inventory.Container.detectAndSendChanges(Container.java:97)
    at com.Hmod.container.ContainerFurnace.detectAndSendChanges(ContainerFurnace.java:158)
    at net.minecraft.entity.player.EntityPlayerMP.onUpdate(EntityPlayerMP.java:263)
    at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2016)
    at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:758)
    at net.minecraft.world.World.updateEntity(World.java:1982)

-- Entity being ticked --
Details:
    Entity Type: null (net.minecraft.entity.player.EntityPlayerMP)
    Entity ID: 263
    Entity Name: Player368
    Entity's Exact location: 58.16, 70.00, 216.79
    Entity's Block location: 58.00,70.00,216.00 - World: (58,70,216), Chunk: (at 10,4,8 in 3,13; contains blocks 48,0,208 to 63,255,223), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
    Entity's Momentum: 0.00, -0.08, 0.00
    Entity's Rider: ~~ERROR~~ NullPointerException: null
    Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
    at net.minecraft.world.World.updateEntities(World.java:1808)
    at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:587)

-- Affected level --
Details:
    Level name: New World
    All players: 1 total; [EntityPlayerMP['Player368'/263, l='New World', x=58.16, y=70.00, z=216.79]]
    Chunk stats: ServerChunkCache: 631 Drop: 0
    Level seed: -6552177684709786455
    Level generator: ID 00 - default, ver 1. Features enabled: true
    Level generator options:
    Level spawn location: 40.00,64.00,236.00 - World: (40,64,236), Chunk: (at 8,4,12 in 2,14; contains blocks 32,0,224 to 47,255,239), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
    Level time: 111186 game time, 1371 day time
    Level dimension: 0
    Level storage version: 0x04ABD - Anvil
    Level weather: Rain time: 3102 (now: false), thunder time: 56965 (now: false)
    Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:774)
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:669)
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:171)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:540)
    at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
    Minecraft Version: 1.8
    Operating System: Windows 7 (amd64) version 6.1
    Java Version: 1.8.0_25, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 745140064 bytes (710 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
    JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M
    IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
    FML: MCP v9.10 FML v8.0.37.1325 Minecraft Forge 11.14.1.1325 4 mods loaded, 4 mods active
    mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
    FML{8.0.37.1325} [Forge Mod Loader] (forgeSrc-1.8-11.14.1.1325.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
    Forge{11.14.1.1325} [Minecraft Forge] (forgeSrc-1.8-11.14.1.1325.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
    hm{1.0} [Harystolho Mod] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
    Loaded coremods (and transformers):
    Profiler Position: N/A (disabled)
    Player Count: 1 / 8; [EntityPlayerMP['Player368'/263, l='New World', x=58.16, y=70.00, z=216.79]]
    Type: Integrated Server (map_client.txt)
    Is Modded: Definitely; Client brand changed to 'fml,forge'