this is my report:

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 5/30/16 5:16 PM
Description: Ticking screen

java.lang.IndexOutOfBoundsException
at java.nio.Buffer.checkIndex(Buffer.java:540)
at java.nio.DirectIntBufferU.get(DirectIntBufferU.java:253)
at bom.a(SourceFile:271)
at bom.a(SourceFile:220)
at ban.a(SourceFile:1694)
at ban.a(SourceFile:1652)
at bln.a(SourceFile:123)
at hd.a(SourceFile:70)
at hd.a(SourceFile:13)
at ej.a(SourceFile:174)
at bct.c(SourceFile:78)
at ban.p(SourceFile:1343)
at ban.ak(SourceFile:774)
at ban.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(Buffer.java:540)
at java.nio.DirectIntBufferU.get(DirectIntBufferU.java:253)
at bom.a(SourceFile:271)
at bom.a(SourceFile:220)
at ban.a(SourceFile:1694)
at ban.a(SourceFile:1652)
at bln.a(SourceFile:123)
at hd.a(SourceFile:70)
at hd.a(SourceFile:13)
at ej.a(SourceFile:174)
at bct.c(SourceFile:78)

– Affected screen –
Details:
Screen name: bct

– 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: Non-integrated multiplayer server
Stacktrace:
at blr.a(SourceFile:289)
at ban.b(SourceFile:1972)
at ban.f(SourceFile:737)
at net.minecraft.client.main.Main.main(SourceFile:148)

– System Details –
Details:
Minecraft Version: 1.7.9
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: 155563040 bytes (148 MB) / 239833088 bytes (228 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: 0, tallocated: 0
Launched Version: 1.7.9
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics 4400 GL version 4.3.0 - Build 10.18.14.4170, 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: [! SoupSkidz Map 8 Pack _2 (1).zip]
Current Language: English (UK)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)

What I expected to happen was
Describe what you thought should happen here: i thought i could just log completely out and back in but no... doesn't work in any version thing. i don't know what the affects version section ment, it just doesn't work in the versions like 1.8.9 or 1.7.9

What actually happened is that it didn't let me enter any server, no multiplayer no singleplayer, everytime it says like logging in it just exits and crashes
it let me get the mojang game uploaded but didn't let me enter any servers, no multiplayer and single player, every time it says logging in it just exits and crashes.

Steps to Reproduce:
1. i just changed my username and it happened.
2. number 1 is false because it happened when i was playing on my mac pro and i didn't even change my username.
3. i am very worried please help me.