Put the summary of the bug you're having here

i logged in 1.7.10 with mods after playing 1.8.1 but it was weird and crashing but never did before and i tried with no mods and it still crashed. crash report: ---- Minecraft Crash Report ----
// Sorry

Time: 05/12/14 11:05 PM
Description: Unexpected error

java.lang.IndexOutOfBoundsException
at java.nio.Buffer.checkIndex(Unknown Source)
at java.nio.DirectIntBufferU.get(Unknown Source)
at bma.a(SourceFile:271)
at bma.a(SourceFile:220)
at bao.a(SourceFile:1694)
at bao.a(SourceFile:1652)
at bjb.a(SourceFile:125)
at hd.a(SourceFile:70)
at hd.a(SourceFile:13)
at ej.a(SourceFile:174)
at bao.p(SourceFile:1585)
at bao.ak(SourceFile:774)
at bao.f(SourceFile:728)
at net.minecraft.client.main.Main.main(SourceFile:148)

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

– Head –
Stacktrace:
at java.nio.Buffer.checkIndex(Unknown Source)
at java.nio.DirectIntBufferU.get(Unknown Source)
at bma.a(SourceFile:271)
at bma.a(SourceFile:220)
at bao.a(SourceFile:1694)
at bao.a(SourceFile:1652)
at bjb.a(SourceFile:125)
at hd.a(SourceFile:70)
at hd.a(SourceFile:13)
at ej.a(SourceFile:174)

– Affected level –
Details:
Level name: MpServer
All players: 0 total; []
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 00 - default, ver 1. 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: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 0 total; []
Retry entities: 0 total; []
Server brand: ~_ERROR~ NullPointerException: null
Server type: Integrated singleplayer server
Stacktrace:
at bjf.a(SourceFile:289)
at bao.b(SourceFile:1972)
at bao.f(SourceFile:742)
at net.minecraft.client.main.Main.main(SourceFile:148)

– System Details –
Details:
Minecraft Version: 1.7.10
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.7.0_67, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 84199584 bytes (80 MB) / 247074816 bytes (235 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: 13, tallocated: 95
Launched Version: 1.7.10
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics GL version 3.1.0 - Build 9.17.10.3347, Intel
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: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: Canadian English (Canada)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)