ProfileNotFoundException cause crash of LAN Server, leading to player reconnecting at spawn point as a new player with no stuff.

• going trough nether portal had cause a server crash. Pretty old java but seems more cause by minecraft rather than jvm. Here's te server console output :

[17:45:44] [Server thread/INFO]: Starting minecraft server version 14w10b
[17:45:44] [Server thread/INFO]: Loading properties
[17:45:44] [Server thread/INFO]: Default game type: SURVIVAL
[17:45:44] [Server thread/INFO]: Generating keypair
[17:45:44] [Server thread/INFO]: Starting Minecraft server on *:25565
[17:45:45] [Server thread/INFO]: Preparing level "world"
[17:45:45] [Server thread/INFO]: Preparing start region for level 0
[17:45:46] [Server thread/INFO]: Preparing spawn area: 46%
[17:45:46] [Server thread/INFO]: Done (1,633s)! For help, type "help" or "?"
[17:46:05] User Authenticator #1/INFO: UUID of player vieuxfaco is 0e0fbbc8cb454dab84427f210b817334
[17:46:05] [Server thread/INFO]: vieuxfaco[/109.205.66.4:45069] logged in with entity id 212 at (119.5, 64.0, 272.5)
[17:46:05] [Server thread/INFO]: vieuxfaco joined the game
[17:49:04] [Server thread/INFO]: vieuxfaco lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}
[17:49:04] [Server thread/INFO]: vieuxfaco left the game
[19:38:45] User Authenticator #2/INFO: UUID of player vieuxfaco is 0e0fbbc8cb454dab84427f210b817334
[19:38:45] [Server thread/INFO]: vieuxfaco[/192.168.1.203:49407] logged in with entity id 7503 at (1369.958741732423, 40.0, 2033.6286893882516)
[19:38:45] [Server thread/INFO]: vieuxfaco joined the game
#

1. A fatal error has been detected by the Java Runtime Environment:
   #
2. SIGSEGV (0xb) at pc=0x00007f1660eb7997, pid=11243, tid=139734062106368
   #
3. JRE version: 6.0_26-b03
4. Java VM: Java HotSpot(TM) 64-Bit Server VM (20.1-b02 mixed mode linux-amd64 compressed oops)
5. Problematic frame:
6. J ny.h()V
   #
7. An error report file with more information is saved as:
8. /srv/galac/minecraft/hs_err_pid11243.log
   #
9. If you would like to submit a bug report, please visit:
10. http://java.sun.com/webapps/bugreport/crash.jsp
    #
    Abandon
    sleeping 3 sec
    [19:41:08] [Server thread/INFO]: Starting minecraft server version 14w10b
    [19:41:08] [Server thread/INFO]: Loading properties
    [19:41:08] [Server thread/INFO]: Default game type: SURVIVAL
    [19:41:08] [Server thread/INFO]: Generating keypair
    [19:41:08] [Server thread/INFO]: Starting Minecraft server on *:25565
    [19:41:09] [Server thread/WARN]: Could not lookup user uuid for 0e0fbbc8-cb45-4dab-8442-7f210b817334
    com.mojang.authlib.yggdrasil.ProfileNotFoundException: Server did not find the requested profile
    at com.mojang.authlib.yggdrasil.YggdrasilGameProfileRepository.findProfilesByNames(YggdrasilGameProfileRepository.java:90) [minecraft_server.14w10b.jar:?]
    at pe.a(SourceFile:57) [minecraft_server.14w10b.jar:?]
    at pe.a(SourceFile:353) [minecraft_server.14w10b.jar:?]
    at my.aF(SourceFile:426) [minecraft_server.14w10b.jar:?]
    at my.g(SourceFile:145) [minecraft_server.14w10b.jar:?]
    at net.minecraft.server.MinecraftServer.run(SourceFile:367) [minecraft_server.14w10b.jar:?]
    at mp.run(SourceFile:667) [minecraft_server.14w10b.jar:?]
    [19:41:09] [Server thread/INFO]: Preparing level "world"
    [19:41:09] [Server thread/INFO]: Preparing start region for level 0
    [19:41:10] [Server thread/INFO]: Preparing spawn area: 32%
    [19:41:11] [Server thread/INFO]: Done (1,843s)! For help, type "help" or "?"
    [19:41:13] User Authenticator #1/INFO: UUID of player vieuxfaco is 0e0fbbc8cb454dab84427f210b817334
    [19:41:13] [Server thread/INFO]: vieuxfaco[/192.168.1.203:49418] logged in with entity id 238 at (116.5, 64.0, 278.5)
    [19:41:13] [Server thread/INFO]: vieuxfaco joined the game

• Got the same server error after reconnecting, but I didn't take server output : it was exactly the same as previous. I crashed when issuing a /gamemode creative from survival mode.

After that I decided to rollback to 14w08b, no anymore debug around this exception. But, 2 hours ago, nobody claimed a ProfileNotFoundException, which is the main problem : player is loosing their stuff.

After some more testing : except my first crash, I DIDN'T manage to reproduce the problem when going through a nether portal.
I didn't test to reprocude /gamemode change

By the way, upgrading server from 14w08a to 14w10b cause all of my player data to be discarded.

Maybe duplicate or complete content of (at least) :
MC-50354 : Player data is wiped when logging onto server.
MC-50359 : character folder getting corrupted every single time no matter what map (new or old)

Regards