Minecraft Forums

Every time I open one of my saved games the game crashes since the 1.4.5 update. I downloaded the prerelease yesterday because of the LAN issues. Here is the error screen and Crash file.

Error Screen:

Minecraft has crashed!
----------------------
Minecraft has stopped running because it encountered a problem; Updating screen events
A full error report has been saved to C:\Users\Stuart\AppData\Roaming\.minecraft\crash-reports\crash-2012-11-20_09.13.52-client.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash

--- BEGIN ERROR REPORT 4455ab --------
Full report at:
C:\Users\Stuart\AppData\Roaming\.minecraft\crash-reports\crash-2012-11-20_09.13.52-client.txt
Please show that file to Mojang, NOT just this screen!
Generated 11/20/12 9:13 AM
-- Head --
Stacktrace:
at aho.h(SourceFile:49)
at aho.<init>(SourceFile:35)
at ahk.<init>(SourceFile:16)
at ahl.a(SourceFile:78)
at net.minecraft.client.Minecraft.a(SourceFile:1369)
at auh.e(SourceFile:157)
at auh.a(SourceFile:122)
at aue.a(SourceFile:71)
at aue.d(SourceFile:125)
at aue.m(SourceFile:110)
-- Affected screen --
Details:
Screen name: bem
Stacktrace:
at net.minecraft.client.Minecraft.l(SourceFile:1085)
at net.minecraft.client.Minecraft.J(SourceFile:582)
at net.minecraft.client.Minecraft.run(SourceFile:534)
at java.lang.Thread.run(Unknown Source)
-- System Details --
Details:
Minecraft Version: 1.4.5
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_09, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 469884136 bytes (448 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: No suspicious classes found.
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
LWJGL: 2.4.2
OpenGL: GeForce GTX 550 Ti/PCIe/SSE2/3DNOW! GL version 4.2.0, NVIDIA Corporation
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Texture Pack: Default
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null
java.lang.RuntimeException: Failed to check session lock, aborting
at aho.h(SourceFile:49)
at aho.<init>(SourceFile:35)
at ahk.<init>(SourceFile:16)
at ahl.a(SourceFile:78)
at net.minecraft.client.Minecraft.a(SourceFile:1369)
at auh.e(SourceFile:157)
at auh.a(SourceFile:122)
at aue.a(SourceFile:71)
at aue.d(SourceFile:125)
at aue.m(SourceFile:110)
at net.minecraft.client.Minecraft.l(SourceFile:1085)
at net.minecraft.client.Minecraft.J(SourceFile:582)
at net.minecraft.client.Minecraft.run(SourceFile:534)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT 3e205f23 ----------


Crash file:
---- Minecraft Crash Report ----
// Who set us up the TNT?


Time: 11/20/12 9:13 AM
Description: Updating screen events

java.lang.RuntimeException: Failed to check session lock, aborting
at aho.h(SourceFile:49)
at aho.<init>(SourceFile:35)
at ahk.<init>(SourceFile:16)
at ahl.a(SourceFile:78)
at net.minecraft.client.Minecraft.a(SourceFile:1369)
at auh.e(SourceFile:157)
at auh.a(SourceFile:122)
at aue.a(SourceFile:71)
at aue.d(SourceFile:125)
at aue.m(SourceFile:110)
at net.minecraft.client.Minecraft.l(SourceFile:1085)
at net.minecraft.client.Minecraft.J(SourceFile:582)
at net.minecraft.client.Minecraft.run(SourceFile:534)
at java.lang.Thread.run(Unknown Source)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
-- Head --
Stacktrace:
at aho.h(SourceFile:49)
at aho.<init>(SourceFile:35)
at ahk.<init>(SourceFile:16)
at ahl.a(SourceFile:78)
at net.minecraft.client.Minecraft.a(SourceFile:1369)
at auh.e(SourceFile:157)
at auh.a(SourceFile:122)
at aue.a(SourceFile:71)
at aue.d(SourceFile:125)
at aue.m(SourceFile:110)
-- Affected screen --
Details:
Screen name: bem
Stacktrace:
at net.minecraft.client.Minecraft.l(SourceFile:1085)
at net.minecraft.client.Minecraft.J(SourceFile:582)
at net.minecraft.client.Minecraft.run(SourceFile:534)
at java.lang.Thread.run(Unknown Source)
-- System Details --
Details:
Minecraft Version: 1.4.5
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_09, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 469884136 bytes (448 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: No suspicious classes found.
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
LWJGL: 2.4.2
OpenGL: GeForce GTX 550 Ti/PCIe/SSE2/3DNOW! GL version 4.2.0, NVIDIA Corporation
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Texture Pack: Default
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null


Please help

java.lang.RuntimeException: Failed to check session lock, aborting

Do you have another copy of Minecraft still running? Or a map editor or similar tool?

This is complaining that minecraft can't grab the file .minecraft/session.lock exclusively.
It could also be a permissions issue.

Thanks, I went into the folder for the save and there was a session.lock file. deleted that and was able to reenter my world. Hope that helps some of the others. I think it has to do with restoring saves from before the username to email conversion.

That file is normally there all the time, and minecraft uses it to make sure that no other program is accessing your world at the same time.
Hopefully it was just a permissions issue.

i have the same problem, but it still wont work