When I tried to chat on a server I expected it to be seen. Instead, Minecraft crashed and shut down. I tried again and the same thing kept on happening.

---- Minecraft Crash Report ----
// Oops.

Time: 7/6/13 4:23 PM
Description: Deserializing Message

java.lang.ClassCastException: com.google.gson.JsonPrimitive cannot be cast to com.google.gson.JsonObject
	at cw.a(SourceFile:14)
	at cw.deserialize(SourceFile:10)
	at com.google.gson.TreeTypeAdapter.read(TreeTypeAdapter.java:58)
	at com.google.gson.Gson.fromJson(Gson.java:795)
	at com.google.gson.Gson.fromJson(Gson.java:761)
	at com.google.gson.Gson.fromJson(Gson.java:710)
	at com.google.gson.Gson.fromJson(Gson.java:682)
	at cu.c(SourceFile:220)
	at bcn.a(SourceFile:518)
	at dl.a(SourceFile:49)
	at cn.b(SourceFile:350)
	at bcn.d(SourceFile:95)
	at bcu.b(SourceFile:60)
	at atn.k(SourceFile:1380)
	at atn.S(SourceFile:662)
	at atn.d(SourceFile:618)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Head --
Stacktrace:
	at cw.a(SourceFile:14)
	at cw.deserialize(SourceFile:10)
	at com.google.gson.TreeTypeAdapter.read(TreeTypeAdapter.java:58)
	at com.google.gson.Gson.fromJson(Gson.java:795)
	at com.google.gson.Gson.fromJson(Gson.java:761)
	at com.google.gson.Gson.fromJson(Gson.java:710)
	at com.google.gson.Gson.fromJson(Gson.java:682)

-- Serialized Message --
Details:
	JSON string: Cannot send chat message.
Stacktrace:
	at cu.c(SourceFile:220)
	at bcn.a(SourceFile:518)
	at dl.a(SourceFile:49)
	at cn.b(SourceFile:350)
	at bcn.d(SourceFile:95)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bcx['TheVampireMiner'/9116575, l='MpServer', x=395.14, y=155.62, z=11.23]]
	Chunk stats: MultiplayerChunkCache: 81
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (390,157,117), Chunk: (at 6,9,5 in 24,7; contains blocks 384,0,112 to 399,255,127), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 757803180 game time, 757849916 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: 1 total; [bcx['TheVampireMiner'/9116575, l='MpServer', x=395.14, y=155.62, z=11.23]]
	Retry entities: 0 total; []
Stacktrace:
	at bcu.a(SourceFile:284)
	at atn.k(SourceFile:1387)
	at atn.S(SourceFile:662)
	at atn.d(SourceFile:618)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bcx['TheVampireMiner'/9116575, l='MpServer', x=395.14, y=155.62, z=11.23]]
	Chunk stats: MultiplayerChunkCache: 81
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (390,157,117), Chunk: (at 6,9,5 in 24,7; contains blocks 384,0,112 to 399,255,127), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 757803180 game time, 757849916 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: 1 total; [bcx['TheVampireMiner'/9116575, l='MpServer', x=395.14, y=155.62, z=11.23]]
	Retry entities: 0 total; []

-- System Details --
Details:
	Minecraft Version: 1.6.1
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_21, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 27914968 bytes (26 MB) / 97406976 bytes (92 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 9107 (509992 bytes; 0 MB) allocated, 14 (784 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.1
	LWJGL: 2.9.0
	OpenGL: ATI Radeon HD 4200  GL version 3.3.9836 Compatibility Profile Context, ATI Technologies Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Sphax PureBDCraft 128x.zip
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 128 (7168 bytes; 0 MB) allocated, 24 (1344 bytes; 0 MB) used

What I expected to happen was that when i sent a chat it would be seen by others and that I would just stay logged on.

What actually happened was Minecraft crashed and shut down.

Steps to Reproduce:
1. Chat on multiplayer.
2. Press enter.
3. Minecraft then crashes.