java -jar minecraft.jar

Exception after login:

Exception in thread "Minecraft main thread" java.lang.UnsatisfiedLinkError: /home/fabianhjr/.minecraft/bin/natives/liblwjgl.so: /home/fabianhjr/.minecraft/bin/natives/liblwjgl.so: wrong ELF class: ELFCLASS32 (Possible cause: architecture word width mismatch)
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1928)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1825)
at java.lang.Runtime.load0(Runtime.java:792)
at java.lang.System.load(System.java:1059)
at org.lwjgl.Sys$1.run(Sys.java:69)
at java.security.AccessController.doPrivileged(Native Method)
at org.lwjgl.Sys.doLoadLibrary(Sys.java:65)
at org.lwjgl.Sys.loadLibrary(Sys.java:81)
at org.lwjgl.Sys.<clinit>(Sys.java:98)
at org.lwjgl.opengl.Display.<clinit>(Display.java:132)
at net.minecraft.client.Minecraft.a(SourceFile:180)
at net.minecraft.client.Minecraft.run(SourceFile:648)
at java.lang.Thread.run(Thread.java:722)

So far I have tried the following:

export LD_LIBRARY_PATH="/opt/java/jre/lib/amd64"
java -Xmx1024M -Xms512M -cp minecraft.jar net.minecraft.LauncherFrame


I am using openJDK 1.7.0, 64 under Fedora 16.

  • Can we please get some more information about your system? Especially architecture and installed Fedora-Version (32 or 64-bit?). This looks like a problem between 32 and 64-bit, like your OS is 64bit but installed java 32bit, or vice versa or similar. – Bobby Jan 22 '12 at 15:20
  • F16(64 Bit), openjdk-1.7.0* for x86_64 – Fabián Heredia Montiel Jan 22 '12 at 15:25
  • 2
    AFAIK openJDK is not supported by minecraft. Try with Sun's JDK. – Maerlyn Jan 22 '12 at 15:28
  • It could be that something went wrong while updating, you could try to get the lates lwjgl binaries yourself for your architecture and try with those. – Bobby Jan 22 '12 at 15:41
  • Not really to do with the question, but are you the LinuxOutlaws Fab? Given the confluence of Linux and Minecraft, it seems likely :D – SaintWacko Jan 23 '12 at 16:44

OpenJDK is not supported by Minecraft. Install Sun's JDK.


For what it's worth, a workaround to continue using OpenJDK is to copy the 64bit native libraries over their 32 bit counterparts, as the issue here is that it is loading the 32bit versions when it expects the 64bit version.

i.e. Copy every whatever64.so in your bin/natives folder over the whatever.so file. However, you will need to do this every update.

You may also need to download the latest LWJGL, depending on your Java version

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