when you do a click with the ender staff on the hand of shield the game crash

Error log

`---- Minecraft Crash Report ----

WARNING: coremods are present:
Contact their authors BEFORE contacting forge

// Everything's going to plan. No, really, that was supposed to happen.

Time: 19/07/16 11:56 PM
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
at com.yyon.grapplinghook.ClientProxyClass.launchplayer(ClientProxyClass.java:236)
at com.yyon.grapplinghook.items.launcherItem.dorightclick(launcherItem.java:61)
at com.yyon.grapplinghook.items.launcherItem.func_77659_a(launcherItem.java:75)
at net.minecraft.item.ItemStack.func_77957_a(ItemStack.java:160)
at net.minecraft.client.multiplayer.PlayerControllerMP.func_187101_a(PlayerControllerMP.java:485)
at PlayerControllerOF.func_187101_a(PlayerControllerOF.java:73)
at net.minecraft.client.Minecraft.func_147121_ag(Minecraft.java:1543)
at net.minecraft.client.Minecraft.func_184117_aA(Minecraft.java:2176)
at net.minecraft.client.Minecraft.func_184118_az(Minecraft.java:1960)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1748)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1056)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:369)
at net.minecraft.client.main.Main.main(SourceFile:124)
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 --
Thread: Client thread
Stacktrace:
at com.yyon.grapplinghook.ClientProxyClass.launchplayer(ClientProxyClass.java:236)
at com.yyon.grapplinghook.items.launcherItem.dorightclick(launcherItem.java:61)
at com.yyon.grapplinghook.items.launcherItem.func_77659_a(launcherItem.java:75)
at net.minecraft.item.ItemStack.func_77957_a(ItemStack.java:160)
at net.minecraft.client.multiplayer.PlayerControllerMP.func_187101_a(PlayerControllerMP.java:485)
at PlayerControllerOF.func_187101_a(PlayerControllerOF.java:73)
at net.minecraft.client.Minecraft.func_147121_ag(Minecraft.java:1543)
at net.minecraft.client.Minecraft.func_184117_aA(Minecraft.java:2176)
at net.minecraft.client.Minecraft.func_184118_az(Minecraft.java:1960)

-- Affected level --
Details:
Level name: MpServer
All players: 1 total; [EntityPlayerSP['Guartinajo'/12, l='MpServer', x=-650,36, y=68,00, z=-289,38]]
Chunk stats: MultiplayerChunkCache: 169, 169
Level seed: 0
Level generator: ID 02 - largeBiomes, ver 0. Features enabled: false
Level generator options:
Level spawn location: World: (-893,65,-897), Chunk: (at 3,4,15 in -56,-57; contains blocks -896,0,-912 to -881,255,-897), Region: (-2,-2; contains chunks -64,-64 to -33,-33, blocks -1024,0,-1024 to -513,255,-513)
Level time: 32370359 game time, 807 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: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 33 total; [EntityBat['Bat'/64, l='MpServer', x=-599,50, y=62,80, z=-305,63], EntityBat['Bat'/65, l='MpServer', x=-596,25, y=63,60, z=-306,75], EntityBat['Bat'/66, l='MpServer', x=-596,27, y=63,60, z=-306,45], EntityBat['Bat'/67, l='MpServer', x=-597,65, y=63,05, z=-306,48], EntityBat['Bat'/68, l='MpServer', x=-600,30, y=62,47, z=-305,65], EntityBat['Bat'/69, l='MpServer', x=-597,55, y=62,52, z=-306,64], EntityBat['Bat'/70, l='MpServer', x=-600,62, y=63,21, z=-305,22], EntityBat['Bat'/71, l='MpServer', x=-600,44, y=62,80, z=-305,29], EntityBat['Bat'/72, l='MpServer', x=-600,62, y=62,98, z=-307,92], EntityPlayerSP['Guartinajo'/12, l='MpServer', x=-650,36, y=68,00, z=-289,38], EntitySheep['Sheep'/14, l='MpServer', x=-689,26, y=75,00, z=-279,51], EntitySquid['Squid'/34, l='MpServer', x=-608,17, y=59,00, z=-336,30], EntitySquid['Squid'/35, l='MpServer', x=-633,82, y=61,02, z=-308,98], EntitySquid['Squid'/36, l='MpServer', x=-627,17, y=62,35, z=-316,29], EntityPig['Pig'/38, l='MpServer', x=-625,22, y=74,00, z=-255,49], EntitySheep['Sheep'/39, l='MpServer', x=-667,55, y=77,00, z=-211,26], EntitySquid['Squid'/45, l='MpServer', x=-596,41, y=56,58, z=-332,99], EntitySquid['Squid'/46, l='MpServer', x=-600,40, y=59,53, z=-324,40], EntitySquid['Squid'/47, l='MpServer', x=-597,09, y=59,88, z=-332,67], EntitySquid['Squid'/48, l='MpServer', x=-602,15, y=59,19, z=-337,80], EntitySquid['Squid'/49, l='MpServer', x=-604,40, y=58,99, z=-330,33], EntitySquid['Squid'/50, l='MpServer', x=-605,53, y=59,95, z=-328,10], EntitySquid['Squid'/51, l='MpServer', x=-588,70, y=60,52, z=-344,48], EntitySquid['Squid'/52, l='MpServer', x=-588,58, y=60,64, z=-346,89], EntitySquid['Squid'/53, l='MpServer', x=-587,84, y=60,57, z=-343,56], EntitySquid['Squid'/55, l='MpServer', x=-592,04, y=61,22, z=-349,77], EntityBat['Bat'/57, l='MpServer', x=-606,27, y=62,59, z=-307,53], EntityBat['Bat'/58, l='MpServer', x=-597,20, y=63,27, z=-306,43], EntityBat['Bat'/59, l='MpServer', x=-598,02, y=63,33, z=-306,42], EntityBat['Bat'/60, l='MpServer', x=-601,70, y=63,21, z=-305,00], EntityBat['Bat'/61, l='MpServer', x=-597,47, y=63,60, z=-306,25], EntityBat['Bat'/62, l='MpServer', x=-596,35, y=63,50, z=-306,51], EntityBat['Bat'/63, l='MpServer', x=-600,39, y=63,01, z=-307,66]]
Retry entities: 0 total; []
Server brand: fml,forge
Server type: Integrated singleplayer server
Stacktrace:
at net.minecraft.client.multiplayer.WorldClient.func_72914_a(WorldClient.java:490)
at net.minecraft.client.Minecraft.func_71396_d(Minecraft.java:2651)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:398)
at net.minecraft.client.main.Main.main(SourceFile:124)
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: 1.9.4
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: 571112384 bytes (544 MB) / 1020067840 bytes (972 MB) up to 1531772928 bytes (1460 MB)
JVM Flags: 7 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xms1024M -Xmx1512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn512M
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 99
FML: MCP 9.28 Powered by Forge 12.17.0.1976 Optifine OptiFine_1.9.4_HD_U_B6 7 mods loaded, 7 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
UCHIJAAAA mcp{9.19} Minecraft Coder Pack
UCHIJAAAA FML{8.0.99.99} Forge Mod Loader
UCHIJAAAA Forge{12.17.0.1976} Minecraft Forge
UCHIJAAAA excore{1.5.3} EXCore
UCHIJAAAA JEI{3.6.8.225} Just Enough Items
UCHIJAAAA FEI{1.0.13} Forever Enough Items
UCHIJAAAA grapplemod{1.9.4-v7} Grappling hook mod
Loaded coremods (and transformers):
GL info: ' Vendor: 'Intel' Version: '4.0.0 - Build 10.18.10.3304' Renderer: 'Intel(R) HD Graphics 4000'
Launched Version: 1.9.4-forge1.9.4-12.17.0.1976
LWJGL: 2.9.4
OpenGL: Intel(R) HD Graphics 4000 GL version 4.0.0 - Build 10.18.10.3304, Intel
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
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)
CPU: net.minecraft.client.Minecraft$15@5b766a7e`

Fixed in version 8