Voici les crash-report :
Time: 6/18/14 12:28 AM
Description: Exception in server tick loop
net.minecraft.server.v1_7_R1.ExceptionWorldConflic
t:
Failed to check session lock, aborting
at net.minecraft.server.v1_7_R1.WorldNBTStorage.check
Session(WorldNBTStorage.java:78)
at net.minecraft.server.v1_7_R1.World.F(World.java:25
42)
at net.minecraft.server.v1_7_R1.WorldServer.a(WorldSe
rver.java:778)
at net.minecraft.server.v1_7_R1.WorldServer.save(Worl
dServer.java:762)
at net.minecraft.server.v1_7_R1.MinecraftServer.saveC
hunks(MinecraftServer.java:359)
at net.minecraft.server.v1_7_R1.MinecraftServer.t(Min
ecraftServer.java:563)
at net.minecraft.server.v1_7_R1.MinecraftServer.run(M
inecraftServer.java:457)
at net.minecraft.server.v1_7_R1.ThreadServerApplicati
on.run(SourceFile:617)