How to fix a cursed account with "crash report"?

I have a problem I can't understand. I run/rent 2 servers, alfa and beta. Both are vanilla servers without mods, alfa is survival and beta creative,

Yesterday when we were playing account 1 suddenly had a game crash (crash report) while playing on server alfa and it seems the problem is on alfa, not on the client.

According to YouTube a crash report can be solved with a driver update on the graphic card, but here's the issue. With the cursed account we can log in and play on server beta without problems. On same computer we can use account 2 on both alfa and beta.

Account 1 still gets the crash report when we shift computers.

Something makes server alfa to deny account1 access the server, but what?

In the multicraft log I have this message:
(TranslatableComponent{key='disconnect.genericReason', args=[Internal Exception: java.io.IOException: Connection reset by peer], siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}})

And according to some forum posts it's because of an IP conflict but no matter if I restart modem, router or computer it will fix the problem.

 

Sorry my bad, this is all new and I'm a bit old And the account which is not working is my 5 yo daughters, so restart the server is not an option. She had put lots of work into this world! Also I live in another timezone.

It also seems more and more to be a multicraft issue and if so, I can't be the only one having this problem. A fix or solution would therefor be most welcome!

---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 2014-07-02 11:30
Description: Rendering item

java.lang.ArrayIndexOutOfBoundsException: 10
at ako.a(SourceFile:149)
at aci.b_(SourceFile:19)
at adb.j(SourceFile:407)
at add.c(SourceFile:99)
at bny.a(SourceFile:285)
at bny.b(SourceFile:400)
at bbv.a(SourceFile:744)
at bbv.a(SourceFile:123)
at blt.b(SourceFile:834)
at bao.ak(SourceFile:801)
at bao.f(SourceFile:728)
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 ako.a(SourceFile:149)
at aci.b_(SourceFile:19)
at adb.j(SourceFile:407)
at add.c(SourceFile:99)
at bny.a(SourceFile:285)

-- Item being rendered --
Details:
Item Type: aci@361bd0
Item Aux: 10
Item NBT: null
Item Foil: false
Stacktrace:
at bny.b(SourceFile:400)
at bbv.a(SourceFile:744)
at bbv.a(SourceFile:123)

-- Affected level --
Details:
Level name: MpServer
All players: 1 total; ['AquaVera'/386657, l='MpServer', x=-483,06, y=79,62, z=-54,03]]
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (-232,64,128), Chunk: (at 8,4,0 in -15,8; contains blocks -240,0,128 to -225,255,143), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Level time: 185736673 game time, 187059559 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 1 total; ['AquaVera'/386657, l='MpServer', x=-483,06, y=79,62, z=-54,03]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Non-integrated multiplayer server
Stacktrace:
at bjf.a(SourceFile:289)
at bao.b(SourceFile:1972)
at bao.f(SourceFile:737)
at net.minecraft.client.main.Main.main(SourceFile:148)

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_45, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 14741872 bytes (14 MB) / 76890112 bytes (73 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
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: 1.7.10
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics 4000 GL version 3.3.0 - Build 8.15.10.2778, Intel
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: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)

Also development console

[11:30:49 INFO]: Client> #@!@# Game crashed! Crash report saved to: #@!@# C:\Users\...\AppData\Roaming\.minecraft\crash-reports\crash-2014-07-02_11.30.49-client.txt
[11:30:50 INFO]: Client> AL lib: (EE) alc_cleanup: 1 device not closed
[11:30:50 ERROR]: Game ended with bad state (exit code -1)
[11:30:50 INFO]: Ignoring visibility rule and showing launcher due to a game crash
[11:30:50 INFO]: Crash report detected, opening: C:\Users\...\AppData\Roaming\.minecraft\crash-reports\crash-2014-07-02_11.30.49-client.txt
[11:30:50 INFO]: Deleting C:\Users\...\AppData\Roaming\.minecraft\versions\1.7.10\1.7.10-natives-80751528778063
[11:30:50 WARN]: Couldn't delete C:\Users\...\AppData\Roaming\.minecraft\versions\1.7.10\1.7.10-natives-80751528778063 - scheduling for deletion upon exit
[11:30:50 INFO]: Reported crash to Mojang (ID 0)

I can''t find any information about the bad state exit code -1

So far Hosthorde has suggest me to re-name the world. When doing so the world/server is working with the cursed account. Changing back the name she (my daughter) can't log in again. The conclusion after this is:
"It does sound like something on the old world is causing the game client to crash. You could try clearing entities in that world using the Essentials /killall command. There may be other plugins that can do this as well."

At the moment I'm strucked at the part: " Essentials /killall ". I can't fin any Essentials in the Multicraft panel and remember, it's a Vanilla server....

 

Minecraftforums.net gave me this solution:

What I suggest is just downloading the world of which the account crashes. From what you describe it may be corrupt.

If your world got corrupted you can try to repair it with MCEdit. Open the offending world in MCEdit, press 'ctrl-i' and select 'Repair regions' in the dialogue which pops up. Once this has completed, save your world and exit MCEdit. To download MCEdit, go tohttp://www.mcedit.net/ and choose the version appropriate for your OS. Once that is done, you can then reupload the world.

What comes to the /killall I don't understand they says:
What your host suggests is to type in the command /killall to get rid of the entities in that particular world, I would assume they already have this (Essentials) installed on your server.

Still can't find Essentials in the MC control panel :/

 

No, turned out giving items with unknown (high) data value crashes and leaves the world unusable.

https://bugs.mojang.com/browse/MC-59807
https://bugs.mojang.com/browse/MC-30484

 

DtigerCSK: I had given up but after your reply and a good night sleep I made a new try. From the bottom of my heart: Thank you!