Minecraft crash, besoin d'aide !

Salut ! J'aurais besoin de votre aide parce que je reçois un rapport de crash quand je lance une partie... Je suis une fille qui ne s'y connait pas trop en informatique, donc je ne comprend rien au rapport !! Est ce que quelqu'un qui s'y connait pourrait m'aider s'il vous plait ? Voilà le détail du rapport : ---- Minecraft Crash Report ----
// I just don't know what went wrong :(

Time: 19/07/13 22:04
Description: Sending packet

java.lang.NullPointerException
at ch.b(SourceFile:107)
at ch.a(SourceFile:39)
at jh.b(SourceFile:430)
at je.a(SourceFile:218)
at je.a(SourceFile:202)
at it.a(SourceFile:127)
at net.minecraft.server.MinecraftServer.r(SourceFile:470)
at net.minecraft.server.MinecraftServer.q(SourceFile:397)
at bjg.q(SourceFile:122)
at net.minecraft.server.MinecraftServer.run(SourceFile:331)
at gp.run(SourceFile:573)


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

-- Head --
Stacktrace:
at ch.b(SourceFile:107)
at ch.a(SourceFile:39)

-- Packet being sent --
Details:
Packet ID: 35
Packet class: es
Stacktrace:
at jh.b(SourceFile:430)
at je.a(SourceFile:218)
at je.a(SourceFile:202)
at it.a(SourceFile:127)
at net.minecraft.server.MinecraftServer.r(SourceFile:470)
at net.minecraft.server.MinecraftServer.q(SourceFile:397)
at bjg.q(SourceFile:122)
at net.minecraft.server.MinecraftServer.run(SourceFile:331)
at gp.run(SourceFile:573)

-- System Details --
Details:
Minecraft Version: 1.5.2
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: 417906720 bytes (398 MB) / 999976960 bytes (953 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 109093 (6109208 bytes; 5 MB) allocated, 109093 (6109208 bytes; 5 MB) used
Suspicious classes: No suspicious classes found.
IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 71
Profiler Position: N/A (disabled)
Vec3 Pool Size: 11890 (665840 bytes; 0 MB) allocated, 11890 (665840 bytes; 0 MB) used
Player Count: 1 / 8; [jc['Gwladys'/80292, l='New world', x=163,56, y=71,00, z=376,44]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.