Q:

ProGuard: Unknown option ' ?ú$B '

(Note: this is not Android.) I wanted to use ProGuard, so I made a jar file of my game and I tried to follow the example provided in README. I got this error:
C:\Java\'Llama World\bin>java -jar C:\Users\-------\Desktop\proguard4.8\lib\prog
uard.jar @llamaworld.jar
Error: Unknown option ' ?ú$B            ' in line 1 of file 'llamaworld.jar',
  included from argument number 1

This is how I made the jar:
jar cvf llamaworld.jar *.class images\*

What is going wrong and how can I fix it?

A:

You are simply providing the wrong arguments to ProGuard. The @ notation is used to specify a configuration file containing a set of command-line parameters which specify what must be done - the JAR files to process are specified differently, using the -injars argument.
Either specify the correct arguments (there's a list at the previous link), or create a configuration file which suits your needs and use that. The manual has several examples; pick the one which fits your scenario best and adapt it to your specific file names etc.

