Cannot reopen world after leaving the game

Please force a crash by holding down F3+C or FN+F3+FC for 10 seconds while in-game and attach the crash report here.

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

Time: 2/3/15 9:45 PM
Description: Manually triggered debug crash

java.lang.Throwable
at bss.r(SourceFile:1570)
at bss.at(SourceFile:880)
at bss.a(SourceFile:317)
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 cem.a(SourceFile:308)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [cin['cire8002'/448, l='MpServer', x=34.50, y=71.00, z=257.50]]
Chunk stats: MultiplayerChunkCache: 503, 503
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: 32.00,64.00,256.00 - World: (32,64,256), Chunk: (at 0,4,0 in 2,16; contains blocks 32,0,256 to 47,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 252 game time, 252 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: 118 total; [afv['Skeleton'/2052, l='MpServer', x=-26.50, y=20.00, z=245.50], agh['Zombie'/2082, l='MpServer', x=-7.50, y=21.00, z=332.50], afv['Skeleton'/2124, l='MpServer', x=-17.13, y=55.00, z=240.47], afv['Skeleton'/2127, l='MpServer', x=54.50, y=46.00, z=311.50], afv['Skeleton'/2128, l='MpServer', x=58.50, y=46.00, z=316.50], abv['Cow'/116, l='MpServer', x=-25.50, y=70.00, z=210.50], abv['Cow'/117, l='MpServer', x=-32.66, y=70.00, z=207.50], abv['Cow'/118, l='MpServer', x=-27.38, y=70.00, z=205.63], abv['Cow'/119, l='MpServer', x=-29.09, y=70.00, z=203.91], abv['Cow'/120, l='MpServer', x=-34.50, y=69.00, z=231.50], abv['Cow'/121, l='MpServer', x=-34.50, y=69.00, z=227.50], abv['Cow'/122, l='MpServer', x=-32.50, y=69.00, z=225.50], abv['Cow'/123, l='MpServer', x=-31.31, y=70.00, z=220.53], abv['Cow'/124, l='MpServer', x=-25.50, y=72.00, z=248.50], abv['Cow'/125, l='MpServer', x=-25.34, y=71.00, z=250.94], abv['Cow'/126, l='MpServer', x=-25.34, y=70.00, z=252.84], abv['Cow'/127, l='MpServer', x=-23.03, y=69.00, z=258.97], abv['Cow'/130, l='MpServer', x=-3.25, y=68.00, z=315.50], abv['Cow'/131, l='MpServer', x=-0.25, y=68.00, z=315.50], abv['Cow'/132, l='MpServer', x=-1.91, y=68.00, z=315.50], abv['Cow'/133, l='MpServer', x=-1.50, y=69.00, z=312.50], abv['Cow'/134, l='MpServer', x=5.50, y=67.00, z=320.50], abv['Cow'/135, l='MpServer', x=2.38, y=67.00, z=319.38], abv['Cow'/136, l='MpServer', x=0.50, y=67.00, z=319.50], abv['Cow'/137, l='MpServer', x=6.44, y=69.00, z=313.28], aeq['Creeper'/2189, l='MpServer', x=53.66, y=44.00, z=319.97], abv['Cow'/142, l='MpServer', x=22.56, y=72.00, z=254.66], agc['Spider'/2190, l='MpServer', x=12.50, y=14.00, z=285.50], abv['Cow'/143, l='MpServer', x=22.88, y=73.00, z=261.22], abv['Cow'/144, l='MpServer', x=19.44, y=73.00, z=257.56], abv['Cow'/145, l='MpServer', x=20.53, y=73.00, z=255.78], acd['Rabbit'/146, l='MpServer', x=31.50, y=69.00, z=335.50], acd['Rabbit'/147, l='MpServer', x=32.34, y=68.00, z=336.34], acd['Rabbit'/148, l='MpServer', x=33.34, y=68.00, z=337.34], abv['Cow'/153, l='MpServer', x=49.50, y=79.00, z=216.13], abv['Cow'/154, l='MpServer', x=49.50, y=79.00, z=217.53], abv['Cow'/155, l='MpServer', x=48.50, y=81.00, z=219.50], abv['Cow'/156, l='MpServer', x=48.50, y=81.00, z=219.50], abv['Cow'/157, l='MpServer', x=47.16, y=71.00, z=250.03], abv['Cow'/158, l='MpServer', x=47.38, y=71.00, z=251.75], abv['Cow'/159, l='MpServer', x=47.56, y=71.00, z=253.53], abv['Cow'/160, l='MpServer', x=56.25, y=71.00, z=250.31], abv['Cow'/161, l='MpServer', x=46.19, y=71.00, z=278.22], abv['Cow'/162, l='MpServer', x=51.50, y=76.00, z=277.50], abv['Cow'/163, l='MpServer', x=46.06, y=71.00, z=280.53], abv['Cow'/164, l='MpServer', x=53.50, y=71.00, z=275.50], abv['Cow'/183, l='MpServer', x=105.09, y=71.00, z=183.50], abv['Cow'/184, l='MpServer', x=103.78, y=71.00, z=183.50], abv['Cow'/185, l='MpServer', x=107.75, y=71.00, z=183.50], abv['Cow'/186, l='MpServer', x=106.31, y=71.00, z=183.50], agc['Spider'/2287, l='MpServer', x=90.50, y=27.00, z=270.50], afv['Skeleton'/2405, l='MpServer', x=24.44, y=62.00, z=314.16], afv['Skeleton'/2406, l='MpServer', x=23.50, y=63.00, z=308.50], afv['Skeleton'/2407, l='MpServer', x=26.50, y=63.00, z=311.50], afv['Skeleton'/2412, l='MpServer', x=14.50, y=48.00, z=234.50], adx['item.tile.gravel'/2474, l='MpServer', x=5.13, y=18.00, z=232.66], agc['Spider'/2507, l='MpServer', x=9.69, y=26.09, z=331.69], agh['Zombie'/2516, l='MpServer', x=93.50, y=60.00, z=275.50], cin['cire8002'/448, l='MpServer', x=34.50, y=71.00, z=257.50], abr['Bat'/499, l='MpServer', x=-20.41, y=57.03, z=248.03], abr['Bat'/502, l='MpServer', x=-20.09, y=54.25, z=234.41], abr['Bat'/505, l='MpServer', x=-16.16, y=54.91, z=243.72], abr['Bat'/507, l='MpServer', x=-25.84, y=55.88, z=253.28], abr['Bat'/509, l='MpServer', x=-20.97, y=54.13, z=243.38], abr['Bat'/510, l='MpServer', x=-27.28, y=57.47, z=251.59], agh['Zombie'/557, l='MpServer', x=32.88, y=25.00, z=333.50], agc['Spider'/558, l='MpServer', x=21.06, y=26.09, z=330.69], adx['item.tile.gravel'/2646, l='MpServer', x=7.13, y=19.00, z=234.88], abr['Bat'/603, l='MpServer', x=-34.59, y=49.03, z=245.88], abr['Bat'/606, l='MpServer', x=-38.31, y=50.88, z=246.16], abr['Bat'/607, l='MpServer', x=-37.03, y=50.00, z=246.19], aeq['Creeper'/2669, l='MpServer', x=47.50, y=14.00, z=279.50], aeq['Creeper'/2670, l='MpServer', x=47.50, y=14.00, z=280.50], afv['Skeleton'/751, l='MpServer', x=49.50, y=17.00, z=230.50], aeq['Creeper'/752, l='MpServer', x=-22.81, y=55.00, z=249.16], aeq['Creeper'/753, l='MpServer', x=-22.50, y=55.00, z=252.50], aeq['Creeper'/754, l='MpServer', x=-18.31, y=55.00, z=250.38], aer['Enderman'/755, l='MpServer', x=-22.50, y=55.00, z=247.50], aeq['Creeper'/2830, l='MpServer', x=84.50, y=46.00, z=331.50], aeq['Creeper'/2831, l='MpServer', x=85.50, y=46.00, z=330.50], aeq['Creeper'/2833, l='MpServer', x=48.50, y=19.00, z=207.50], abr['Bat'/811, l='MpServer', x=-19.88, y=54.34, z=246.09], abr['Bat'/812, l='MpServer', x=-18.41, y=55.16, z=244.34], abr['Bat'/813, l='MpServer', x=-22.09, y=54.09, z=242.81], abr['Bat'/814, l='MpServer', x=-28.09, y=55.56, z=254.69], agh['Zombie'/936, l='MpServer', x=-12.50, y=37.00, z=185.50], afv['Skeleton'/1053, l='MpServer', x=66.50, y=19.00, z=243.50], agc['Spider'/1142, l='MpServer', x=71.50, y=18.00, z=240.50], aeq['Creeper'/1143, l='MpServer', x=69.50, y=18.00, z=238.50], adx['item.tile.gravel'/5254, l='MpServer', x=4.41, y=18.00, z=231.88], adx['item.tile.gravel'/5262, l='MpServer', x=7.88, y=19.00, z=234.88], aeq['Creeper'/1225, l='MpServer', x=18.50, y=38.00, z=254.50], afv['Skeleton'/1294, l='MpServer', x=62.50, y=26.00, z=220.50], afv['Skeleton'/1295, l='MpServer', x=60.63, y=26.00, z=220.06], agh['Zombie'/1352, l='MpServer', x=52.50, y=18.00, z=219.50], agh['Zombie'/1353, l='MpServer', x=51.50, y=18.00, z=218.50], afv['Skeleton'/1354, l='MpServer', x=52.50, y=18.00, z=217.50], agc['Spider'/1394, l='MpServer', x=42.50, y=16.00, z=309.50], afv['Skeleton'/1407, l='MpServer', x=9.50, y=15.00, z=184.50], agh['Zombie'/1408, l='MpServer', x=9.50, y=15.00, z=180.50], agh['Zombie'/1434, l='MpServer', x=27.34, y=45.00, z=197.34], agc['Spider'/1435, l='MpServer', x=-14.72, y=55.63, z=245.94], aeq['Creeper'/1476, l='MpServer', x=14.50, y=43.00, z=215.50], aeq['Creeper'/1477, l='MpServer', x=15.50, y=43.00, z=215.50], afv['Skeleton'/1478, l='MpServer', x=15.56, y=43.00, z=211.84], afv['Skeleton'/1479, l='MpServer', x=112.50, y=19.00, z=258.50], aeq['Creeper'/1540, l='MpServer', x=-33.50, y=16.00, z=267.50], aeq['Creeper'/1541, l='MpServer', x=-29.50, y=16.00, z=266.50], adw['Falling Block'/1575, l='MpServer', x=-16.50, y=24.27, z=372.50], afv['Skeleton'/1779, l='MpServer', x=45.50, y=30.00, z=321.50], agh['Zombie'/1841, l='MpServer', x=58.19, y=46.00, z=332.66], agh['Zombie'/1842, l='MpServer', x=53.50, y=46.00, z=330.50], afv['Skeleton'/1877, l='MpServer', x=79.50, y=28.00, z=230.50], afv['Skeleton'/1929, l='MpServer', x=78.84, y=21.50, z=227.44], aeq['Creeper'/1967, l='MpServer', x=108.50, y=22.00, z=197.50], afv['Skeleton'/1973, l='MpServer', x=-43.50, y=16.00, z=286.50], afv['Skeleton'/1985, l='MpServer', x=52.06, y=33.00, z=215.47], afv['Skeleton'/1986, l='MpServer', x=46.50, y=35.00, z=216.66]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Integrated singleplayer server
Stacktrace:
at cem.a(SourceFile:308)
at bss.b(SourceFile:2278)
at bss.a(SourceFile:326)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.1
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: 232839200 bytes (222 MB) / 419983360 bytes (400 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: 1.8.1
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics GL version 4.2.0 - Build 10.18.10.3412, 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: No
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: N/A (disabled)