Potential Cause
This Issue is potentially caused by Antivirus Programs and/or Firewall Programs, especially Norton. Try disabling it while launching Minecraft and see if it helps. If it does maybe consider using a different Antivirus Program.
Also, this issue might easily be fixed by reinstalling Minecraft.
[17:00:51 WARN]: No assets index file C:\Users\Manuel-7\AppData\Roaming\.minecraft\assets\virtual\legacy; can't reconstruct assets
java.io.FileNotFoundException: File '/Users/test/Library/Application Support/minecraft/assets/indexes/legacy.json' does not exist
at org.apache.commons.io.FileUtils.openInputStream(FileUtils.java:299) ~[launcher.jar:?]
at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:1711) ~[launcher.jar:?]
at net.minecraft.launcher.GameLauncher.getAssetObject(GameLauncher.java:323) ~[launcher.jar:?]
at net.minecraft.launcher.GameLauncher.launchGame(GameLauncher.java:245) ~[launcher.jar:?]
at net.minecraft.launcher.GameLauncher.onDownloadJobFinished(GameLauncher.java:616) [launcher.jar:?]
at net.minecraft.launcher.updater.download.DownloadJob.popAndDownload(DownloadJob.java:120) [launcher.jar:?]
at net.minecraft.launcher.updater.download.DownloadJob.access$000(DownloadJob.java:12) [launcher.jar:?]
at net.minecraft.launcher.updater.download.DownloadJob$1.run(DownloadJob.java:89) [launcher.jar:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439) [?:1.6.0_65]
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) [?:1.6.0_65]
at java.util.concurrent.FutureTask.run(FutureTask.java:138) [?:1.6.0_65]
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895) [?:1.6.0_65]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918) [?:1.6.0_65]
at java.lang.Thread.run(Thread.java:695) [?:1.6.0_65]
Related crash log:
Macs:
[media][media]Windows:
[media]Related issues
is duplicated by
Attachments
Comments


I have this issue as well. It should be noted I have an older laptop, and also should be noted I accidently downloaded a 32bit version of Java on my 64bit computer (prior to this update it still worked fine), and I was too lazy to change it. As I press Play Game, it loads the game regularly up until the Mojang screen comes up. Graphics for Mojang screen seem extremely low-resolution and irregular. Hopefully we can get an answer soon. Need be I can report my crash data as well.
EDIT- I realize this post is for Mac OS but I use Windows Vista.

ubuntu 13.10
java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.5-b02, mixed mode)
Minecraft 1.7.9

I am seeing this same problem in a more recent version: 1.7.9. It is almost like the problem has been inherited by some of the more recent versions of Minecraft which is weird since it was almost non-existent in 1.6.

Happens to me in 1.7.x

@Will Eder I have a 2002 computer, Windows XP, and it happens to me

I have a regular windows 7 x64 laptop and downloaded minecraft from https://minecraft.net/
What ever I do the error about missing legacy.json occur.
What can I do to make it work?

Same issue, same system.

Update: This Issue is, at least on Windows, most likely caused by Antivirus programs. One known program that can potentially cause it is "Norton 360"

@Galaxy_2Alex I don't have Norton 360 but I do use Microsoft Security Essentials. After re-downloading the minecraft files it worked fine.

[21:42:53 FATAL]: Fatal error launching game. Report this to http://bugs.mojang.com please!
java.io.FileNotFoundException: File '/home/ewhac/.minecraft/assets/indexes/legacy.json' does not exist
at org.apache.commons.io.FileUtils.openInputStream(FileUtils.java:299) ~[launcher.jar:?]
at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:1711) ~[launcher.jar:?]
at net.minecraft.launcher.Launcher.cleanupOrphanedAssets(Launcher.java:186) ~[launcher.jar:?]
at net.minecraft.launcher.Launcher.performCleanups(Launcher.java:421) ~[launcher.jar:?]
at net.minecraft.launcher.game.MinecraftGameRunner.launchGame(MinecraftGameRunner.java:217) ~[launcher.jar:?]
at com.mojang.launcher.game.runner.AbstractGameRunner.onDownloadJobFinished(AbstractGameRunner.java:177) [launcher.jar:?]
at com.mojang.launcher.updater.download.DownloadJob.popAndDownload(DownloadJob.java:122) [launcher.jar:?]
at com.mojang.launcher.updater.download.DownloadJob.access$000(DownloadJob.java:12) [launcher.jar:?]
at com.mojang.launcher.updater.download.DownloadJob$1.run(DownloadJob.java:86) [launcher.jar:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [?:1.7.0_65]
at java.util.concurrent.FutureTask.run(FutureTask.java:262) [?:1.7.0_65]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [?:1.7.0_65]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [?:1.7.0_65]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_65]
Some system info:
$ java -version
java version "1.7.0_65"
OpenJDK Runtime Environment (IcedTea 2.5.1) (7u65-2.5.1-2)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)
$ uname -a
Linux trivium 3.14-1-amd64 #1 SMP Debian 3.14.12-1 (2014-07-11) x86_64 GNU/Linux
$ ls -al .minecraft/assets/indexes/
total 168
drwxr-xr-x 2 ewhac ewhac 4096 Jul 17 02:28 .
drwxr-xr-x 4 ewhac ewhac 4096 Mar 17 20:58 ..
-rw-r--r-- 1 ewhac ewhac 88092 Jul 22 21:42 1.7.10.json
-rw-r--r-- 1 ewhac ewhac 73081 Apr 22 00:58 1.7.4.json

I'm getting this with 1.5.1 using 1.7.10 and 14w32d. I have no idea why it does this because the game always runs perfectly fine.

Also affects 1.8 on Linux 3.13.0-35-generic #62-Ubuntu; game does not run fine, but loses map data.

I am not aware of any norton program for Linux, and do not have such installed. Also, the game is not installed on Linux, but run straight out of a jar. I replaced the jar, no change. Principle effect of the error; my map, my terraformed map, is gone, and I now appear deep underground, not in a cavern, but suffocating in the midst of blocks, in some strange world. A much smaller world.

Rolled back to an older version, managed to load, no error, map still funny. Now using 1.8, no error, map wrong.

What is the web address of all the asset downloads? It's usually possible to add domains to firewall whitelists, and firewall programs usually add their own site + update source there. If I can get the address of Minecraft asset downloads then I'm all good.

Tip: I would only recommend to uninstall Norton, when reinstalling Minecraft isn't working!!! Mods please change this! I guess payed(monthly) security is more important than a one time payed game!
PLEASE MODS, change the work around description! Else some player could uninstall NORTON and then catch a virus and you would be the person reponsible

Word to the wise concerning the apparent conflict with antivirus software programs, always have a backup ready to go if you are even thinking of uninstalling or disabling ANY security software for any reason such as that stated above by the Mods.

I have uninstalled JAVA and Minecraft and reinstalled and continue to get this error. I use Kaspersky and I don't believe anything has changed, this error just started occurring two days ago. What is the resolution.

You must remove Minecrafts support files as well. On Mac the folder is located in ~/Library/Application Support/minecraft
The only files you would need to save are the world files in saves. Then there are the options file and the server list. I do not know where the server list is stored.
Someone else could help you out with the Windows location.
That should stop this error.

the windows location is
%appdata%\.minecraft
and it is only the "assets", "libraries", and "versions" folders that you will have to delete under most circumstances
EDIT: useful link for getting a hold of the mods: http://www.reddit.com/r/Mojira/

I deleted the file recommended from the .minecraft folder and it downloaded new versions. Then when I attempted to get on a multiplayer server I got Game ended with bad state (exit code 1). I deleted versions and tried again and got
Game ended with bad state (exit code 255). Any more suggestions? Thanks.

This message can be benign although disconcerting. Nothing bad happened despite these logs:
[11:55:01 INFO]: Looking for orphaned versions to clean up...
[11:55:01 FATAL]: Fatal error launching game. Report this to http://bugs.mojang.com please!
java.io.FileNotFoundException: File 'C:\Users*************\Desktop\MCSERVER\New folder\.minecraft\assets\indexes\legacy.json' does not exist
[13:04:18 INFO]: Game ended with no troubles detected (exit code 0)

I looked in it and I think this file is just a hash index of all the resources in the assets folder. You could delete the assets folder to force an update, but this is a possible workaround and not a fix.

Got it on newest snapshot (15w32c):
[media]game still launched though... first "Game Output" entry is at 14:20:20

Getting this same error on Minecraft Launcher 1.6.13.
What's the solution? It prevents game play. a blocker in IMHO.

I have this issue as well. However if I login with another user account on my PC and start a new world, it doesn't complain about a missing legacy.json, although it doesn't exist. Is it possible, that it's only required for worlds created with older versions of the game?
Anyway: Wouldn't it be possible to put a legacy.json as an attachment to this case, so anyone who is missing it can download it?

Just noticed this issue on Mac OS 10.11.4 when looking through the log after what I assume was an unrelated crash.
[11:03:00 INFO]: Minecraft Launcher 1.6.61 (through bootstrap 5) started on osx...
[11:03:00 INFO]: Current time is Jul 4, 2016 11:03:00 AM
[11:03:00 INFO]: System.getProperty('os.name') == 'Mac OS X'
[11:03:00 INFO]: System.getProperty('os.version') == '10.11.4'
[11:03:00 INFO]: System.getProperty('os.arch') == 'x86_64'
[11:03:00 INFO]: System.getProperty('java.version') == '1.8.0_60'
[11:03:00 INFO]: System.getProperty('java.vendor') == 'Oracle Corporation'
[11:03:00 INFO]: System.getProperty('sun.arch.data.model') == '64'
[...]
11:05:11 FATAL]: Fatal error launching game. Report this to http://bugs.mojang.com please!
java.io.FileNotFoundException: File '/Users/tasnu/Library/Application Support/minecraft/assets/indexes/legacy.json' does not exist
at org.apache.commons.io.FileUtils.openInputStream(FileUtils.java:299) ~[launcher.jar:1.6.61]
at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:1711) ~[launcher.jar:1.6.61]
at net.minecraft.launcher.Launcher.cleanupOrphanedAssets(Launcher.java:254) ~[launcher.jar:1.6.61]
at net.minecraft.launcher.Launcher.performCleanups(Launcher.java:496) ~[launcher.jar:1.6.61]
at net.minecraft.launcher.game.MinecraftGameRunner.launchGame(MinecraftGameRunner.java:231) ~[launcher.jar:1.6.61]
at com.mojang.launcher.game.runner.AbstractGameRunner.onDownloadJobFinished(AbstractGameRunner.java:186) [launcher.jar:1.6.61]
at com.mojang.launcher.updater.download.DownloadJob.popAndDownload(DownloadJob.java:122) [launcher.jar:1.6.61]
at com.mojang.launcher.updater.download.DownloadJob.access$000(DownloadJob.java:12) [launcher.jar:1.6.61]
at com.mojang.launcher.updater.download.DownloadJob$1.run(DownloadJob.java:86) [launcher.jar:1.6.61]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_60]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_60]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_60]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_60]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_60]

@Hugo, your stack is the benign version I mentioned above.
The problem is indicated by
at net.minecraft.launcher.GameLauncher.getAssetObject(GameLauncher.java:323) ~[launcher.jar:?]
at net.minecraft.launcher.GameLauncher.launchGame(GameLauncher.java:245) ~[launcher.jar:?]
The benign version has
at net.minecraft.launcher.Launcher.cleanupOrphanedAssets(Launcher.java:254) ~[launcher.jar:1.6.61]
at net.minecraft.launcher.Launcher.performCleanups(Launcher.java:496) ~[launcher.jar:1.6.61]
at net.minecraft.launcher.game.MinecraftGameRunner.launchGame(MinecraftGameRunner.java:231) ~[launcher.jar:1.6.61]
One is attempting to access the file to get the assets and run the game. The other is speculatively attempting to clean up after the game has already exited. [All failures should really be being silently suppressed by Mojang during cleanup, but they don't do that]

Is this still a concern in the current Minecraft Launcher version 2.0.805 / 2.0.806? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.
Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. It will be reopened it as soon as the requested information has been delivered.

I can't test this with the new launcher since it crashes on one of my kids computers with a CPU error.
Fact is that when using the legacy laucnher something does not handle the filenotfound exception, which it should ignore since it is a legcy cleanup. Please fix.