Hopper: dk: Error while parsing: TranslatableComponent{key='multiplayer.player.joined', args=[KH3L4Dz], siblings=[], style=Style{hasParent=false, color=?e, bo

dk: Error while parsing: TranslatableComponent{key='multiplayer.player.joined', args=[KH3L4Dz], siblings=[], style=Style{hasParent=false, color=?e, bold=null, italic=null, underlined=null, obfuscated=null}}
	at dj.e(SourceFile:79)
	at dj.c(SourceFile:125)
	at net.minecraft.server.MinecraftServer.a(SourceFile:736)
	at hw.a(SourceFile:747)
	at hw.a(SourceFile:752)
	at hw.a(SourceFile:94)
	at bnq.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.t(SourceFile:481)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bnn.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hr.run(SourceFile:575)
Caused by: java.util.FormatFlagsConversionMismatchException: Conversion = s, Flags =  
	at java.util.Formatter$FormatSpecifier.failMismatch(Formatter.java:4041)
	at java.util.Formatter$FormatSpecifier.checkBadFlags(Formatter.java:2949)
	at java.util.Formatter$FormatSpecifier.checkGeneral(Formatter.java:2907)
	at java.util.Formatter$FormatSpecifier.<init>(Formatter.java:2680)
	at java.util.Formatter.parse(Formatter.java:2528)
	at java.util.Formatter.format(Formatter.java:2469)
	at java.util.Formatter.format(Formatter.java:2423)
	at java.lang.String.format(String.java:2797)
	at dj.e(SourceFile:76)
	... 11 more

---- Minecraft Crash Report ----
// Surprise! Haha. Well, this is awkward.

Time: 07/09/13 04:53 ?
Description: Exception in server tick loop

dk: Error while parsing: TranslatableComponent{key='multiplayer.player.joined', args=[KH3L4Dz], siblings=[], style=Style{hasParent=false, color=?e, bold=null, italic=null, underlined=null, obfuscated=null}}
	at dj.e(SourceFile:79)
	at dj.c(SourceFile:125)
	at net.minecraft.server.MinecraftServer.a(SourceFile:736)
	at hw.a(SourceFile:747)
	at hw.a(SourceFile:752)
	at hw.a(SourceFile:94)
	at bnq.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.t(SourceFile:481)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bnn.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hr.run(SourceFile:575)
Caused by: java.util.FormatFlagsConversionMismatchException: Conversion = s, Flags =  
	at java.util.Formatter$FormatSpecifier.failMismatch(Formatter.java:4041)
	at java.util.Formatter$FormatSpecifier.checkBadFlags(Formatter.java:2949)
	at java.util.Formatter$FormatSpecifier.checkGeneral(Formatter.java:2907)
	at java.util.Formatter$FormatSpecifier.<init>(Formatter.java:2680)
	at java.util.Formatter.parse(Formatter.java:2528)
	at java.util.Formatter.format(Formatter.java:2469)
	at java.util.Formatter.format(Formatter.java:2423)
	at java.lang.String.format(String.java:2797)
	at dj.e(SourceFile:76)
	... 11 more


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

-- System Details --
Details:
	Minecraft Version: 13w36b
	Operating System: Mac OS X (x86_64) version 10.7.5
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 59641448 bytes (56 MB) / 218955776 bytes (208 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 556 (31136 bytes; 0 MB) allocated, 513 (28728 bytes; 0 MB) used
	IntCache: cache: 1, tcache: 1, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 110 (6160 bytes; 0 MB) allocated, 74 (4144 bytes; 0 MB) used
	Player Count: 0 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.