Cows cause crash

Cows causing crash, all I know was my brother did something with a cow on our lan world, and goodbye,,,

---- Minecraft Crash Report ----
// Why did you do that?

Time: 4/15/17 10:33 AM
Description: Unexpected error

java.lang.ArrayIndexOutOfBoundsException: -1
	at java.util.ArrayList.elementData(ArrayList.java:418)
	at java.util.ArrayList.remove(ArrayList.java:495)
	at qn.b(SourceFile:70)
	at bgu.aw(SourceFile:989)
	at bgu.a(SourceFile:399)
	at net.minecraft.client.main.Main.main(SourceFile:123)


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

-- Head --
Thread: Client thread
Stacktrace:
	at java.util.ArrayList.elementData(ArrayList.java:418)
	at java.util.ArrayList.remove(ArrayList.java:495)

-- Affected level --
Details:
	Level name: MpServer
	All players: 2 total; [bsw['GiantNuker'/16750, l='MpServer', x=-105.30, y=50.00, z=136.49], bsx['PistoneNutter'/21877, l='MpServer', x=-53.78, y=64.27, z=142.08]]
	Chunk stats: MultiplayerChunkCache: 164, 164
	Level seed: 0
	Level generator: ID 04 - customized, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-127,35,232), Chunk: (at 1,2,8 in -8,14; contains blocks -128,0,224 to -113,255,239), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 85975 game time, 6199 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: 70 total; [yx['Cow'/25866, l='MpServer', x=-127.13, y=64.00, z=188.64], yx['Cow'/25868, l='MpServer', x=-126.19, y=64.00, z=188.50], yx['Cow'/25871, l='MpServer', x=-108.67, y=64.00, z=172.29], yx['Cow'/25873, l='MpServer', x=-121.39, y=64.00, z=183.80], yx['Cow'/25875, l='MpServer', x=-106.55, y=64.00, z=175.00], yx['Cow'/25878, l='MpServer', x=-125.26, y=64.00, z=189.37], yx['Cow'/25885, l='MpServer', x=-107.57, y=64.00, z=174.74], yx['Cow'/25891, l='MpServer', x=-109.14, y=64.00, z=173.06], abl['item.item.seeds'/28452, l='MpServer', x=-93.58, y=64.00, z=197.40], yx['Cow'/25896, l='MpServer', x=-126.21, y=64.00, z=185.63], yx['Cow'/25899, l='MpServer', x=-125.05, y=64.00, z=188.08], zm['Wolf'/16433, l='MpServer', x=-181.26, y=64.00, z=112.63], yx['Cow'/25906, l='MpServer', x=-110.88, y=64.00, z=208.94], zm['Wolf'/16434, l='MpServer', x=-184.28, y=70.00, z=138.49], bsx['PistoneNutter'/21877, l='MpServer', x=-53.78, y=64.27, z=142.08], yx['Cow'/25922, l='MpServer', x=-125.66, y=64.00, z=187.50], yx['Cow'/25924, l='MpServer', x=-126.37, y=64.00, z=189.08], yx['Cow'/25929, l='MpServer', x=-110.27, y=64.00, z=208.19], zm['Wolf'/16457, l='MpServer', x=-170.50, y=64.00, z=140.31], zm['Wolf'/16458, l='MpServer', x=-165.50, y=64.00, z=136.60], zm['Wolf'/16459, l='MpServer', x=-171.22, y=64.00, z=156.23], zm['Wolf'/16460, l='MpServer', x=-166.35, y=65.00, z=144.69], zm['Wolf'/16461, l='MpServer', x=-165.50, y=64.00, z=189.75], yw['Chicken'/16462, l='MpServer', x=-166.11, y=74.00, z=203.24], yx['Cow'/25935, l='MpServer', x=-108.59, y=64.00, z=173.21], yw['Chicken'/16463, l='MpServer', x=-165.43, y=74.00, z=201.50], yw['Chicken'/16464, l='MpServer', x=-170.21, y=75.00, z=201.50], yx['Cow'/25937, l='MpServer', x=-110.16, y=64.00, z=209.96], yw['Chicken'/16465, l='MpServer', x=-166.50, y=74.00, z=201.22], zm['Wolf'/16466, l='MpServer', x=-164.46, y=64.00, z=192.09], yx['Cow'/25946, l='MpServer', x=-95.02, y=64.00, z=199.88], zc['Parrot'/27740, l='MpServer', x=-58.75, y=62.00, z=134.75], yx['Cow'/25949, l='MpServer', x=-92.23, y=64.00, z=198.77], zm['Wolf'/16482, l='MpServer', x=-155.32, y=68.00, z=77.50], zm['Wolf'/16485, l='MpServer', x=-156.65, y=73.00, z=97.38], zm['Wolf'/16486, l='MpServer', x=-146.51, y=64.00, z=155.36], yx['Cow'/25960, l='MpServer', x=-126.05, y=64.00, z=187.97], zm['Wolf'/16488, l='MpServer', x=-155.31, y=64.00, z=162.76], zm['Wolf'/16489, l='MpServer', x=-155.45, y=64.00, z=164.48], zm['Wolf'/16490, l='MpServer', x=-166.28, y=65.00, z=185.45], yx['Cow'/25967, l='MpServer', x=-82.27, y=66.00, z=198.69], yx['Cow'/25969, l='MpServer', x=-106.56, y=64.00, z=173.80], bsx['PistoneNutter'/21877, l='MpServer', x=-53.78, y=64.27, z=142.08], yx['Cow'/25973, l='MpServer', x=-80.61, y=66.00, z=199.59], zm['Wolf'/27767, l='MpServer', x=-163.50, y=65.00, z=86.50], zm['Wolf'/16504, l='MpServer', x=-132.27, y=67.00, z=92.49], yx['Cow'/25977, l='MpServer', x=-94.52, y=64.00, z=199.43], zm['Wolf'/16505, l='MpServer', x=-135.69, y=67.00, z=104.00], zm['Wolf'/16506, l='MpServer', x=-139.24, y=67.00, z=108.30], zm['Wolf'/16507, l='MpServer', x=-122.78, y=65.00, z=99.50], zc['Parrot'/16508, l='MpServer', x=-132.35, y=67.00, z=94.60], yx['Cow'/25982, l='MpServer', x=-105.93, y=64.00, z=174.80], zm['Wolf'/16510, l='MpServer', x=-143.36, y=64.00, z=165.62], yw['Chicken'/16511, l='MpServer', x=-137.19, y=64.00, z=174.57], yw['Chicken'/16513, l='MpServer', x=-133.47, y=65.00, z=204.13], yx['Cow'/25986, l='MpServer', x=-82.16, y=66.00, z=199.59], yw['Chicken'/16514, l='MpServer', x=-136.16, y=65.00, z=207.39], yx['Cow'/25996, l='MpServer', x=-94.79, y=64.00, z=198.75], yx['Cow'/25999, l='MpServer', x=-93.04, y=64.00, z=198.32], bsx['PistoneNutter'/21877, l='MpServer', x=-19.27, y=65.03, z=160.86], yx['Cow'/26001, l='MpServer', x=-110.05, y=64.00, z=209.39], yx['Cow'/26003, l='MpServer', x=-93.42, y=64.00, z=198.92], yx['Cow'/26009, l='MpServer', x=-94.07, y=64.00, z=199.27], yx['Cow'/26014, l='MpServer', x=-79.95, y=66.00, z=199.43], yx['Cow'/26016, l='MpServer', x=-93.77, y=64.00, z=200.77], yx['Cow'/26020, l='MpServer', x=-94.54, y=64.00, z=199.95], zc['Parrot'/25025, l='MpServer', x=-101.07, y=76.00, z=140.77], bsx['PistoneNutter'/17897, l='MpServer', x=-95.39, y=64.00, z=140.20], bsw['GiantNuker'/16750, l='MpServer', x=-105.30, y=50.00, z=136.49], zm['Wolf'/27895, l='MpServer', x=-181.28, y=66.00, z=83.44]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bqu.a(SourceFile:365)
	at bgu.b(SourceFile:2529)
	at bgu.a(SourceFile:413)
	at net.minecraft.client.main.Main.main(SourceFile:123)

-- System Details --
Details:
	Minecraft Version: 17w15a
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 127333552 bytes (121 MB) / 532692992 bytes (508 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
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 17w15a
	LWJGL: 2.9.4
	OpenGL: AMD Radeon(TM) R5 Graphics GL version 4.5.13399 Compatibility Profile Context 15.201.1101.0, ATI Technologies Inc.
	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: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: 
	Current Language: English (US)
	Profiler Position: [UNKNOWN]
	CPU: 4x AMD A8-6410 APU with AMD Radeon R5 Graphics