Hopper: java.lang.NullPointerException: Updating screen events

java.lang.NullPointerException: Updating screen events
	at byl.a(SourceFile:371)
	at bxf.k(SourceFile:414)
	at bxf.p(SourceFile:382)

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

Time: 16/01/15 12:25 PM
Description: Updating screen events

java.lang.NullPointerException: Updating screen events
	at byl.a(SourceFile:371)
	at bxf.k(SourceFile:414)
	at bxf.p(SourceFile:382)
	at bst.s(SourceFile:1494)
	at bst.au(SourceFile:886)
	at bst.a(SourceFile:321)
	at net.minecraft.client.main.Main.main(SourceFile:124)


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

-- Head --
Stacktrace:
	at byl.a(SourceFile:371)
	at bxf.k(SourceFile:414)
	at bxf.p(SourceFile:382)

-- Affected screen --
Details:
	Screen name: bzj

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [cio['MaikolGaymerXxxx'/1891, l='MpServer', x=-404,63, y=63,00, z=46,44]]
	Chunk stats: MultiplayerChunkCache: 121, 121
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: -240,00,64,00,220,00 - World: (-240,64,220), Chunk: (at 0,4,12 in -15,13; contains blocks -240,0,208 to -225,255,223), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 115881 game time, 115881 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: true), thunder time: 0 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
	Forced entities: 33 total; [acq['Calamar'/17205, l='MpServer', x=-390,66, y=57,91, z=-12,19], acq['Calamar'/17204, l='MpServer', x=-389,72, y=61,53, z=-15,78], ady['item.tile.sapling.birch'/18146, l='MpServer', x=-369,13, y=64,00, z=67,88], adm['entity.ItemFrame.name'/1765, l='MpServer', x=-394,50, y=64,50, z=45,03], acq['Calamar'/17206, l='MpServer', x=-383,59, y=60,00, z=-10,03], ady['item.tile.sapling.birch'/18289, l='MpServer', x=-366,50, y=64,00, z=70,13], acq['Calamar'/17184, l='MpServer', x=-411,97, y=59,84, z=92,25], acq['Calamar'/17185, l='MpServer', x=-464,84, y=50,69, z=2,09], abw['Vaca'/1779, l='MpServer', x=-343,75, y=79,00, z=89,28], abw['Vaca'/1776, l='MpServer', x=-364,13, y=82,00, z=20,69], acq['Calamar'/17189, l='MpServer', x=-419,69, y=62,58, z=28,82], acq['Calamar'/17190, l='MpServer', x=-431,31, y=48,22, z=32,31], cio['MaikolGaymerXxxx'/1891, l='MpServer', x=-404,63, y=63,00, z=46,44], abw['Vaca'/1893, l='MpServer', x=-358,38, y=77,00, z=0,13], acq['Calamar'/17168, l='MpServer', x=-431,19, y=52,88, z=18,44], acq['Calamar'/17182, l='MpServer', x=-399,50, y=58,94, z=96,88], acq['Calamar'/17181, l='MpServer', x=-405,72, y=61,63, z=97,94], abs['Murcielago'/17987, l='MpServer', x=-388,25, y=44,10, z=26,75], abv['Pollo'/1751, l='MpServer', x=-400,53, y=64,00, z=64,28], acq['Calamar'/17161, l='MpServer', x=-443,97, y=53,47, z=87,63], acq['Calamar'/17166, l='MpServer', x=-425,31, y=54,50, z=9,81], acq['Calamar'/17164, l='MpServer', x=-447,28, y=50,88, z=88,63], acq['Calamar'/17268, l='MpServer', x=-441,44, y=50,09, z=34,09], acq['Calamar'/17270, l='MpServer', x=-435,97, y=50,88, z=23,38], ady['item.tile.sapling.acacia'/17965, l='MpServer', x=-368,13, y=64,00, z=84,00], acq['Calamar'/17250, l='MpServer', x=-465,69, y=48,00, z=24,59], ady['item.tile.sapling.birch'/17922, l='MpServer', x=-370,13, y=64,00, z=68,88], acq['Calamar'/17829, l='MpServer', x=-451,81, y=53,41, z=16,41], acq['Calamar'/17828, l='MpServer', x=-456,25, y=48,03, z=23,88], acq['Calamar'/17830, l='MpServer', x=-457,47, y=48,03, z=20,03], acq['Calamar'/17825, l='MpServer', x=-459,03, y=52,97, z=88,97], acq['Calamar'/17827, l='MpServer', x=-453,53, y=46,00, z=22,22], acq['Calamar'/17826, l='MpServer', x=-459,22, y=47,41, z=8,56]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at cen.a(SourceFile:309)
	at bst.b(SourceFile:2293)
	at bst.a(SourceFile:330)
	at net.minecraft.client.main.Main.main(SourceFile:124)

-- System Details --
Details:
	Minecraft Version: 1.8.2-pre4
	Operating System: Linux (i386) version 3.2.0-3-686-pae
	Java Version: 1.6.0_26, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Server VM (mixed mode), Sun Microsystems Inc.
	Memory: 85229064 bytes (81 MB) / 533921792 bytes (509 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 1 total; -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 1.8.2-pre4
	LWJGL: 2.9.1
	OpenGL: Mesa DRI Intel(R) Sandybridge Mobile x86/MMX/SSE2 GL version 3.0 Mesa 8.0.5, Tungsten Graphics, 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: Español (Venezuela)
	Profiler Position: N/A (disabled)