Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
Completely ignored arguments: [--nativeLauncherVersion, 308]
[20:02:50] [Client thread/INFO]: Setting user: UnJU24iedPVp
[20:02:50] [Client thread/INFO]: (Session ID is <censored>)
Exception in thread "Client thread" java.lang.NullPointerException
at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:213)
at com.google.common.collect.Lists$ReverseList.<init>(Lists.java:767)
at com.google.common.collect.Lists.reverse(Lists.java:759)
at lt.b(SourceFile:156)
at lt.<init>(SourceFile:43)
at net.minecraft.server.MinecraftServer.<init>(SourceFile:155)
at bpo.<init>(SourceFile:41)
at ave.<init>(SourceFile:293)
at net.minecraft.client.main.Main.main(SourceFile:124)

This shows up when I try to play vanilla Minecraft 1.8 - 1.8.9. Why does it do so and how can I fix this?


The JIRA page for this bug suggests that it is caused by the 'usercache.json' file being corrupted.

You can fix it by deleting the file:

Open your Minecraft launcher, and click 'Edit Profile' in the bottom left hand corner. Then, click 'Open Game Dir' in the bottom right of the window that pops up. Scroll down to find the 'usercache.json' file, and delete it. Now try opening Minecraft again.

Hope this helped :)

  • Thx, i figured how how to scrub minecraft just before u sent it ;D – Edward Oct 11 '16 at 13:07
  • No problem, happy to help :) – Sulphate Oct 12 '16 at 15:40

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