Crashed when clicked in the multiplayer button.I reported to Mojang many times,It was have a log in screen (a lot of dirt block of background). It was crashed and showed
'Completely ignored arguments: [--nativeLauncherVersion, 286]
[19:14:58] [Client thread/INFO]: Setting user: Misterleo040814
[19:14:58] [Client thread/INFO]: (Session ID is token:474370f0e33040cebb5167e4f9e6997b:0c8562f094444c36a58570978ba05a9f)
[19:15:00] [Client thread/INFO]: LWJGL Version: 2.9.4
[19:15:01] [Client thread/INFO]: Reloading ResourceManager: Default
[19:15:02] [Sound Library Loader/INFO]: Starting up SoundSystem...
[19:15:03] [Thread-6/INFO]: Initializing LWJGL OpenAL
[19:15:03] [Thread-6/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[19:15:03] [Thread-6/INFO]: OpenAL initialized.
[19:15:03] [Sound Library Loader/INFO]: Sound engine started
[19:15:05] [Client thread/INFO]: Created: 512x512 textures-atlas
[19:15:10] [Client thread/FATAL]: Reported exception thrown!
e: Rendering screen
at bfk.a(SourceFile:1065) ~[1.8.8.jar:?]
at ave.av(SourceFile:915) ~[1.8.8.jar:?]
at ave.a(SourceFile:325) [1.8.8.jar:?]
at net.minecraft.client.main.Main.main(SourceFile:124) [1.8.8.jar:?]
Caused by: java.lang.IllegalArgumentException: bad Base64 input character at 13581: 0 (decimal)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247) ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197) ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188) ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at azk.c(SourceFile:212) ~[1.8.8.jar:?]
at azk.a(SourceFile:145) ~[1.8.8.jar:?]
at awd.a(SourceFile:25) ~[1.8.8.jar:?]
at awi.b(SourceFile:412) ~[1.8.8.jar:?]
at awi.a(SourceFile:211) ~[1.8.8.jar:?]
at azh.a(SourceFile:291) ~[1.8.8.jar:?]
at bfk.a(SourceFile:1039) ~[1.8.8.jar:?]
... 3 more
---- Minecraft Crash Report ----
// You should try our sister game, Minceraft!

Time: 2015/10/2 下午 7:15
Description: Rendering screen

java.lang.IllegalArgumentException: bad Base64 input character at 13581: 0 (decimal)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at azk.c(SourceFile:212)
at azk.a(SourceFile:145)
at awd.a(SourceFile:25)
at awi.b(SourceFile:412)
at awi.a(SourceFile:211)
at azh.a(SourceFile:291)
at bfk.a(SourceFile:1039)
at ave.av(SourceFile:915)
at ave.a(SourceFile:325)
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 io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at azk.c(SourceFile:212)
at azk.a(SourceFile:145)
at awd.a(SourceFile:25)
at awi.b(SourceFile:412)
at awi.a(SourceFile:211)
at azh.a(SourceFile:291)

– Screen render details –
Details:
Screen name: azh
Mouse location: Scaled: (326, 216). Absolute: (653, 590)
Screen size: Scaled: (640, 512). Absolute: (1280, 1024). Scale factor of 2
Stacktrace:
at bfk.a(SourceFile:1039)
at ave.av(SourceFile:915)
at ave.a(SourceFile:325)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.8
Operating System: Windows XP (x86) version 5.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 97550984 bytes (93 MB) / 216580096 bytes (206 MB) up to 523501568 bytes (499 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.8.8
LWJGL: 2.9.4
OpenGL: ATI Radeon HD 4250 GL version 3.2.9756 Compatibility Profile Context, 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: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: 繁體中文 (台灣)(Chinese)
Profiler Position: N/A (disabled)
CPU: 4x AMD Phenom(tm) II X4 955 Processor
#@Unable to render embedded object: File (@# Game crashed) not found. Crash report saved to: #@!@# C:\Documents and Settings\Administrator\Application Data\.minecraft\crash-reports\crash-2015-10-02_19.15.10-client.txt
AL lib: (EE) alc_cleanup: 1 device not closed
Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release'
Please help me fix this bug.
file:
---- Minecraft Crash Report ----
// Why is it breaking

Time: 2015/10/3 下午 12:23
Description: Rendering screen

java.lang.IllegalArgumentException: bad Base64 input character at 13581: 0 (decimal)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at azk.c(SourceFile:212)
at azk.a(SourceFile:145)
at awd.a(SourceFile:25)
at awi.b(SourceFile:412)
at awi.a(SourceFile:211)
at azh.a(SourceFile:291)
at bfk.a(SourceFile:1039)
at ave.av(SourceFile:915)
at ave.a(SourceFile:325)
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 io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at azk.c(SourceFile:212)
at azk.a(SourceFile:145)
at awd.a(SourceFile:25)
at awi.b(SourceFile:412)
at awi.a(SourceFile:211)
at azh.a(SourceFile:291)

– Screen render details –
Details:
Screen name: azh
Mouse location: Scaled: (305, 207). Absolute: (611, 609)
Screen size: Scaled: (640, 512). Absolute: (1280, 1024). Scale factor of 2
Stacktrace:
at bfk.a(SourceFile:1039)
at ave.av(SourceFile:915)
at ave.a(SourceFile:325)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.8
Operating System: Windows XP (x86) version 5.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 113971200 bytes (108 MB) / 225447936 bytes (215 MB) up to 523501568 bytes (499 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.8.8
LWJGL: 2.9.4
OpenGL: ATI Radeon HD 4250 GL version 3.2.9756 Compatibility Profile Context, 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: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: 繁體中文 (台灣)(Chinese)
Profiler Position: N/A (disabled)
CPU: 4x AMD Phenom(tm) II X4 955 Processor