Have you ever gotten an error like this?
Planet M.U.L.E. Error
/home/geek/mule/data/lib/liblwjgl.so: wrong ELF class: ELFCLASS32 (Possible cause: architecture word width mismatch) Please run mule.sh to start the game.
Well, do not worry, here is the solution. The reason you are getting this error is that mule.sh is trying to use a 32 bit library instead of a 64 bit library like your machine probably requires. I got this error when launching the game M.U.L.E. for the first time on a 64 bit linux box. The only thing you need to do to fix this error is change the LD_LIBRAY_PATH in your mule.sh file as follows.
The old line looked like this: export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH so change it to: export LD_LIBRARY_PATH=.:/usr/lib/jvm/java-7-openjdk/jre/lib/amd64
Your library path may be different. In order to find what LD_LIBRARY_PATH to change to, I ran the following command:
$ locate jre/lib | grep 64
This assumes that you have recently run the updatedb command, and have the openjdk installed, but it shows all of the files in the java runtime library that mule needs. Your java runtime library may be on a different path.
Hope that helps.