This is the error report I got when i told my child to chop down tree / Shall we play a game?
[removed duplicate issue]

THIS IS WHAT I GOT WHEN MY CHILD MINED A MODDED BLOCK

---- Minecraft Crash Report ----
// Would you like a cupcake?

Time: 2/19/14 6:24 PM
Description: Ticking entity

java.lang.NullPointerException
at net.minecraft.item.ItemStack.func_77984_f(ItemStack.java:243)
at net.minecraft.item.ItemStack.func_77972_a(ItemStack.java:359)
at mca.chore.ChoreMining.doHarvestBlock(ChoreMining.java:582)
at mca.chore.ChoreMining.runActiveAI(ChoreMining.java:425)
at mca.chore.ChoreMining.runChoreAI(ChoreMining.java:171)
at mca.entity.AbstractEntity.updateChores(AbstractEntity.java:2795)
at mca.entity.AbstractEntity.func_70071_h_(AbstractEntity.java:286)
at mca.entity.AbstractChild.func_70071_h_(AbstractChild.java:50)
at mca.entity.EntityPlayerChild.func_70071_h_(EntityPlayerChild.java:254)
at net.minecraft.world.World.func_72866_a(World.java:2350)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:719)
at net.minecraft.world.World.func_72870_g(World.java:2311)
at net.minecraft.world.World.func_72939_s(World.java:2157)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:550)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:668)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:129)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)

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

-- Head --
Stacktrace:
at net.minecraft.item.ItemStack.func_77984_f(ItemStack.java:243)
at net.minecraft.item.ItemStack.func_77972_a(ItemStack.java:359)
at mca.chore.ChoreMining.doHarvestBlock(ChoreMining.java:582)
at mca.chore.ChoreMining.runActiveAI(ChoreMining.java:425)
at mca.chore.ChoreMining.runChoreAI(ChoreMining.java:171)
at mca.entity.AbstractEntity.updateChores(AbstractEntity.java:2795)
at mca.entity.AbstractEntity.func_70071_h_(AbstractEntity.java:286)
at mca.entity.AbstractChild.func_70071_h_(AbstractChild.java:50)
at mca.entity.EntityPlayerChild.func_70071_h_(EntityPlayerChild.java:254)
at net.minecraft.world.World.func_72866_a(World.java:2350)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:719)
at net.minecraft.world.World.func_72870_g(World.java:2311)

-- Entity being ticked --
Details:
Entity Type: mca.EntityPlayerChild (mca.entity.EntityPlayerChild)
Entity ID: 33
Entity Name: entity.mca.EntityPlayerChild.name
Entity's Exact location: -1814.27, 5.00, -676.30
Entity's Block location: World: (-1815,5,-677), Chunk: (at 9,0,11 in -114,-43; contains blocks -1824,0,-688 to -1809,255,-673), Region: (-4,-2; contains chunks -128,-64 to -97,-33, blocks -2048,0,-1024 to -1537,255,-513)
Entity's Momentum: 0.00, -0.08, 0.00
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:2157)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:550)

-- Affected level --
Details:
Level name: MVA
All players: 1 total; [EntityPlayerMP['dame404'/48, l='MVA', x=-1814.30, y=6.00, z=-677.17]]
Chunk stats: ServerChunkCache: 1072 Drop: 0
Level seed: 171585397
Level generator: ID 01 - flat, ver 0. Features enabled: true
Level generator options: 2;7,2x3,2;1;village
Level spawn location: World: (-1142,4,-433), Chunk: (at 10,0,15 in -72,-28; contains blocks -1152,0,-448 to -1137,255,-433), Region: (-3,-1; contains chunks -96,-32 to -65,-1, blocks -1536,0,-512 to -1025,255,-1)
Level time: 48358 game time, 48358 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 65053 (now: false), thunder time: 2946 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:668)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:129)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)

-- System Details --
Details:
Minecraft Version: 1.6.4
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 312785840 bytes (298 MB) / 625016832 bytes (596 MB) up to 954466304 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
AABB Pool Size: 1324 (74144 bytes; 0 MB) allocated, 521 (29176 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v8.11 FML v6.4.49.965 Minecraft Forge 9.11.1.965 6 mods loaded, 6 mods active
mcp{8.09} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
FML{6.4.49.965} Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Forge{9.11.1.965} Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
cfm{3.2.7} §4MrCrayfish's Furniture Mod Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
mca{3.6.0b} [Minecraft Comes Alive](MCA-3.6.0b MC-1.6.4.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
moreplayermodels{1.6.4} MorePlayerModels Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 1645 (92120 bytes; 0 MB) allocated, 922 (51632 bytes; 0 MB) used
Player Count: 1 / 8; [EntityPlayerMP['dame404'/48, l='MVA', x=-1814.30, y=6.00, z=-677.17]]
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'fml,forge'