Unable to chat

"/ / I feel sad now 😞 Deserializing Message 7/4/13 GMT +8 10:24pm Crash Problem

I joined a server and expected everything to be working normally. especially with the chat.
Before I had updated Minecraft the chat was working fine with no crashes or problems. I expected nothing to be different but whenever I type, it crashes.
I tried to type in chat and Minecraft crashed instantly, I tried to restart Minecraft but it still crashed but somehow the /msg command on servers still work.
I wanted to comminucate with the people on the server and just pressed the T button and typed the words. However, when I pressed the Enter key, Minecraft crashed instantly and it showed a message, like this,"/ / I feel sad now 😞 Time: 7/4/13 10:24pm Description: Deserializing Message."

Steps to Reproduce:
1. Log in to a multiplayer server with the updated version. (1.6.1)
2. Press the T button and chat
3. Minecraft crashes and displays a message like the one above.
(I attached the log file with it below)

---- Minecraft Crash Report ----
// I feel sad now :(

Time: 7/4/13 10:24 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: 4 total; [bcx['Minecart131'/649880, l='MpServer', x=42.80, y=69.12, z=156.07], ben['super_slasher'/640160, l='MpServer', x=43.47, y=64.25, z=167.00], ben['jacob051904'/573941, l='MpServer', x=42.31, y=66.00, z=154.69], ben['Old_Mesarth'/649248, l='MpServer', x=46.09, y=63.88, z=127.78]]
	Chunk stats: MultiplayerChunkCache: 81
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (18,65,158), Chunk: (at 2,4,14 in 1,9; contains blocks 16,0,144 to 31,255,159), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 54432982 game time, 54794002 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: 9 total; [bcx['Minecart131'/649880, l='MpServer', x=42.80, y=69.12, z=156.07], ben['super_slasher'/640160, l='MpServer', x=43.47, y=64.25, z=167.00], ben['Old_Mesarth'/649248, l='MpServer', x=46.09, y=63.88, z=127.78], ben['jacob051904'/573941, l='MpServer', x=42.31, y=66.00, z=154.69], tc['Creeper'/648659, l='MpServer', x=64.06, y=50.00, z=180.53], ben['Old_Mesarth'/649248, l='MpServer', x=46.09, y=63.88, z=127.78], tc['Creeper'/648660, l='MpServer', x=60.41, y=50.00, z=180.00], ben['super_slasher'/640160, l='MpServer', x=43.47, y=64.25, z=167.00], ben['jacob051904'/573941, l='MpServer', x=42.31, y=66.00, z=154.69]]
	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: 4 total; [bcx['Minecart131'/649880, l='MpServer', x=42.80, y=69.12, z=156.07], ben['super_slasher'/640160, l='MpServer', x=43.47, y=64.25, z=167.00], ben['jacob051904'/573941, l='MpServer', x=42.31, y=66.00, z=154.69], ben['Old_Mesarth'/649248, l='MpServer', x=46.09, y=63.88, z=127.78]]
	Chunk stats: MultiplayerChunkCache: 81
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (18,65,158), Chunk: (at 2,4,14 in 1,9; contains blocks 16,0,144 to 31,255,159), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 54432982 game time, 54794002 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: 9 total; [bcx['Minecart131'/649880, l='MpServer', x=42.80, y=69.12, z=156.07], ben['super_slasher'/640160, l='MpServer', x=43.47, y=64.25, z=167.00], ben['Old_Mesarth'/649248, l='MpServer', x=46.09, y=63.88, z=127.78], ben['jacob051904'/573941, l='MpServer', x=42.31, y=66.00, z=154.69], tc['Creeper'/648659, l='MpServer', x=64.06, y=50.00, z=180.53], ben['Old_Mesarth'/649248, l='MpServer', x=46.09, y=63.88, z=127.78], tc['Creeper'/648660, l='MpServer', x=60.41, y=50.00, z=180.00], ben['super_slasher'/640160, l='MpServer', x=43.47, y=64.25, z=167.00], ben['jacob051904'/573941, l='MpServer', x=42.31, y=66.00, z=154.69]]
	Retry entities: 0 total; []

-- System Details --
Details:
	Minecraft Version: 1.6.1
	Operating System: Mac OS X (x86_64) version 10.7.5
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 72035880 bytes (68 MB) / 121798656 bytes (116 MB) up to 1069416448 bytes (1019 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 7955 (445480 bytes; 0 MB) allocated, 71 (3976 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
	Launched Version: 1.6.1
	LWJGL: 2.9.0
	OpenGL: Intel GMA X3100 OpenGL Engine GL version 2.1 APPLE-7.4.1, Intel Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Faithful Texture Pack
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 945 (52920 bytes; 0 MB) allocated, 28 (1568 bytes; 0 MB) used