Hopper: java.lang.UnsupportedOperationException: Unexpected change in protocol to HANDSHAKING

java.lang.UnsupportedOperationException: Unexpected change in protocol to HANDSHAKING
	at bkr.a(SourceFile:126)
	at eg.a(SourceFile:159)
	at bkq.a(SourceFile:245)
	at bgz.c(SourceFile:108)

---- Minecraft Crash Report ----
// Hi. I'm Minecraft, and I'm a crashaholic.

Time: 26/02/14 12:28
Description: Ticking screen

java.lang.UnsupportedOperationException: Unexpected change in protocol to null
	at bkr.a(SourceFile:126)
	at eg.a(SourceFile:159)
	at bkq.a(SourceFile:245)
	at bgz.c(SourceFile:108)
	at azl.p(SourceFile:1318)
	at azl.ah(SourceFile:757)
	at azl.f(SourceFile:711)
	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 bkr.a(SourceFile:126)
	at eg.a(SourceFile:159)
	at bkq.a(SourceFile:245)
	at bgz.c(SourceFile:108)

-- Affected screen --
Details:
	Screen name: bgz
Stacktrace:
	at azl.p(SourceFile:1318)
	at azl.ah(SourceFile:757)
	at azl.f(SourceFile:711)
	at net.minecraft.client.main.Main.main(SourceFile:148)

-- System Details --
Details:
	Minecraft Version: 1.7.5
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 241457456 bytes (230 MB) / 343408640 bytes (327 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 1.7.5
	LWJGL: 2.9.1
	OpenGL: GeForce GT 525M/PCI/SSE2 GL version 4.1.0, NVIDIA Corporation
	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: []
	Current Language: Français (France)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Anisotropic Filtering: Off (1)