Minecraft crahes whilst running Custom NPC's

---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 31/08/15 16:01
Description: Unexpected error

java.lang.IndexOutOfBoundsException
at java.nio.Buffer.checkIndex(Buffer.java:540)
at java.nio.DirectIntBufferU.get(DirectIntBufferU.java:253)
at net.minecraft.client.renderer.RenderGlobal.func_72712_a(RenderGlobal.java:350)
at net.minecraft.client.renderer.RenderGlobal.func_72732_a(RenderGlobal.java:294)
at net.minecraft.client.Minecraft.func_71353_a(Minecraft.java:2205)
at net.minecraft.client.Minecraft.func_71403_a(Minecraft.java:2135)
at net.minecraft.client.network.NetHandlerPlayClient.func_147282_a(NetHandlerPlayClient.java:239)
at net.minecraft.network.play.server.S01PacketJoinGame.func_148833_a(SourceFile:70)
at net.minecraft.network.play.server.S01PacketJoinGame.func_148833_a(SourceFile:13)
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:2050)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:962)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:887)
at net.minecraft.client.main.Main.main(SourceFile:148)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)


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

-- Head --
Stacktrace:
at java.nio.Buffer.checkIndex(Buffer.java:540)
at java.nio.DirectIntBufferU.get(DirectIntBufferU.java:253)
at net.minecraft.client.renderer.RenderGlobal.func_72712_a(RenderGlobal.java:350)
at net.minecraft.client.renderer.RenderGlobal.func_72732_a(RenderGlobal.java:294)
at net.minecraft.client.Minecraft.func_71353_a(Minecraft.java:2205)
at net.minecraft.client.Minecraft.func_71403_a(Minecraft.java:2135)
at net.minecraft.client.network.NetHandlerPlayClient.func_147282_a(NetHandlerPlayClient.java:239)
at net.minecraft.network.play.server.S01PacketJoinGame.func_148833_a(SourceFile:70)
at net.minecraft.network.play.server.S01PacketJoinGame.func_148833_a(SourceFile:13)
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212)

-- Affected level --
Details:
Level name: MpServer
All players: 0 total; []
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options:
Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 0 game time, 0 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Forced entities: 0 total; []
Retry entities: 0 total; []
Server brand: ~~ERROR~~ NullPointerException: null
Server type: Integrated singleplayer server
Stacktrace:
at net.minecraft.client.multiplayer.WorldClient.func_72914_a(WorldClient.java:373)
at net.minecraft.client.Minecraft.func_71396_d(Minecraft.java:2433)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:916)
at net.minecraft.client.main.Main.main(SourceFile:148)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 86344568 bytes (82 MB) / 326692864 bytes (311 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v9.05 FML v7.10.85.1230 Minecraft Forge 10.13.2.1230 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{7.10.85.1230} [Forge Mod Loader] (forge-1.7.10-10.13.2.1230.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Forge{10.13.2.1230} [Minecraft Forge] (forge-1.7.10-10.13.2.1230.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
customnpcs{1.7.10c} [CustomNpcs] (CustomNPCs_1.7.10c.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Launched Version: 1.7.10-Forge10.13.2.1230
LWJGL: 2.9.1
OpenGL: GeForce GTX 650/PCIe/SSE2 GL version 4.4.0, NVIDIA Corporation
GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Packs: []
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)