Can't play multiplayer

I load the launcher, and then click Play. When the minecraft window loads and I click multiplayer, a crash window appears.

---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 6/16/15 12:10 PM
Description: Rendering screen

java.lang.IllegalArgumentException: bad Base64 input character at 9942: 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:914)
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: (250, 138). Absolute: (500, 202)
Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2
Stacktrace:
at bfk.a(SourceFile:1039)
at ave.av(SourceFile:914)
at ave.a(SourceFile:325)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.7
Operating System: Windows 8.1 (amd64) version 6.3
CPU: 2x AMD Athlon(tm) Dual Core Processor 4850e
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 24198352 bytes (23 MB) / 213458944 bytes (203 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: 0, tallocated: 0
Launched Version: 1.8.7
LWJGL: 2.9.4
OpenGL: Radeon X1650 Series GL version 2.1.8545 Release, ATI Technologies Inc.
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because ARB_framebuffer_object 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)