Minecraft Forums

Hey guys. I think my computer crashed the other day whilst hosting and now this error comes up.

[[09:06:59 ERROR]: Exception reading .\world\level.dat
java.util.zip.ZipException: Not in GZIP format
at java.util.zip.GZIPInputStream.readHeader(Unknown Source) ~[?:1.7.0_40]
at java.util.zip.GZIPInputStream.<init>(Unknown Source) ~[?:1.7.0_40]
at java.util.zip.GZIPInputStream.<init>(Unknown Source) ~[?:1.7.0_40]
at dr.a(SourceFile:12) ~[minecraft_server.1.7.2.jar:?]
at axd.c(SourceFile:56) [minecraft_server.1.7.2.jar:?]
at awz.b(SourceFile:88) [minecraft_server.1.7.2.jar:?]
at net.minecraft.server.MinecraftServer.a(SourceFile:123) [minecraft_server.1.7.2.jar:?]
at net.minecraft.server.MinecraftServer.a(SourceFile:165) [minecraft_server.1.7.2.jar:?]
at lj.e(SourceFile:186) [minecraft_server.1.7.2.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:328) [minecraft_server.1.7.2.jar:?]
at ky.run(SourceFile:617) [minecraft_server.1.7.2.jar:?]

The server still runs and I am still able to log in, but this error is unnerving.
Is there a way to fix this issue?

Thanks

Your level.dat appears to have been corrupted. If you have a backup you might consider whether you want to restore it.
I'm not sure what the implications are for rolling this back on a server, but in single player worlds the level.dat also contains the player's inventory and location.

Downgrade to 1.6.4 run it join then upgrade to 1.7.2 again

I wouldn't advise doing that, unless you like potentially further corrupting your world.
1.7 introduced lots of changes that 1.6 won't understand. Your save may not have any of those changes in it (new items, blocks, biomes), but it might.