Minecraft Forums

Fixed Update:

The problem, as I first concluded below, was not a java memory space issue, but a file issue. After my world crashed, the files got all screwed up. Inside my world folder in %appdata% > .minecraft > saves > {my world}, my level data was presented as: level.dat_mcr (I inserted a screen shot of this file. You might have to scroll down)

The problem was this file. I followed this video's instructions and got my world back!

My Original Post:

I was playing on one of my custom worlds, and it's a fairly large world, I used AMIDST because I was having trouble finding a nether fortress. I teleported to the fortress, but had to switch to spectator because I was inside of a wall. After I made sure that it was actually a fortress, I went to teleport back to my nether portal where I began (I planned on continuing from there in survival). I'm not sure if my coordinates were too close to the nether portal or what, but the second I teleported my world crashed, and this showed up:

---- Minecraft Crash Report ----
// There are four lights!

Time: 1/31/16 2:42 PM
Description: Exception in server tick loop

java.lang.OutOfMemoryError: Java heap space
	at java.util.ArrayList.<init>(ArrayList.java:152)
	at com.google.common.collect.Lists.newArrayListWithCapacity(Lists.java:175)
	at du.a(SourceFile:63)
	at dn.a(SourceFile:406)
	at dn.a(SourceFile:70)
	at dn.a(SourceFile:406)
	at dn.a(SourceFile:70)
	at dx.a(SourceFile:106)
	at dx.a(SourceFile:71)
	at dx.a(SourceFile:67)
	at anj.a(SourceFile:58)
	at ld.e(SourceFile:129)
	at ld.c(SourceFile:81)
	at lc$a.<init>(SourceFile:39)
	at lc.a(SourceFile:231)
	at lc.a(SourceFile:263)
	at lx.a(SourceFile:225)
	at lx.c(SourceFile:277)
	at lx.a(SourceFile:132)
	at lo.b(SourceFile:110)
	at lo.c(SourceFile:56)
	at ek.a(SourceFile:221)
	at ll.c(SourceFile:168)
	at net.minecraft.server.MinecraftServer.B(SourceFile:625)
	at net.minecraft.server.MinecraftServer.A(SourceFile:535)
	at bpo.A(SourceFile:152)
	at net.minecraft.server.MinecraftServer.run(SourceFile:451)
	at java.lang.Thread.run(Thread.java:745)


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

-- System Details --
Details:
	Minecraft Version: 1.8.9
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 879340744 bytes (838 MB) / 1060372480 bytes (1011 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [lf['RenSword'/437, l='Perfect Mountain House', x=70.00, y=90.00, z=50.00]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

I don't know how to fix this and I need help. I can start up minecraft and load all of my other worlds perfectly normal, just not this one which really sucks because I had so much stuff built into this world (I might just quit if I can't play it again).

Also, I have tried using NBTexplorer to change the position of my player. It hasn't helped. AMIDST does not seem to be the issue, as it was working perfectly fine the first couple of times I teleported to the Nether fortresses.

I have never used mods or changed my minecraft from the way it originally was when I downloaded it.

System details:

Minecraft 1.8.9

Java: Windows Offline (64-bit)

Computer: 6GB 64 bit

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I figured out that this problem actually had nothing to do with the amount of memory I had. In my files folder, my world's level data was saved as: level.dat_mcr

This video showed me how to fix it, and my world opened up perfectly fine after that! Yay!

Video

How do I go about doing that?

grimallq,

I tried it and it didn't work (also I knew how to do this, it just didn't work for me before so I figured I was doing it wrong), but thanks for your input. I didn't find it common knowledge. In fact, I find that I didn't ask for your attitude when I posted my thread; I asked for help. But thanks for the unnecessary stuff. (I am genuinely grateful for your attempt to help, so thank you.)

I didn't find the newbie news report or the common knowledge bit to be of any significant influence to my situation. Still, I appreciate you trying

What does "It didn't work" mean?

The exact same thing happened and the same crash screen showed up.

This thread claims this crash happened to them due to world corruption: http://goodfella-gaming.com/forum/viewtopic.php?t=3017

(It's not the exception alone, but the exception plus the stack trace that makes it the same crash)

Thankfully I found how to fix it with video. The problem happened to be an issue where my level data was saving as: level.dat_mcr This created problems when trying to load it.

Thank you both for helping!

level.dat_mcr is a backup made when your world was upgraded from mcregion to anvil format.

level.dat_old would have been a more recent backup.

edit: oh I see you added your directory listing and you don't have the dat_old... weird.

But you can see that your dat_mcr is old (from december)