Hi Carlo, Try to run your commamd from C:\ecj and then complete the path to the param file. ---- Mensaje original --- De: Carlo Rossi <[log in to unmask]> Enviado: 16 de noviembre de 2010 11/16/10 Para: [log in to unmask] Asunto: problem launching tutorial1 Hello, sorry to bother you with this apparently not-ECJ problem but at this point Java installation seems fine to me and I still can't launch the tutorial1 (and it worked months ago!) with this command: java ec.Evolve -file tutorial1.params The error is this: C:\ecj\ec\app\tutorial1>java ec.Evolve -file tutorial1.params Exception in thread "main" java.lang.NoClassDefFoundError: ec/Evolve Caused by: java.lang.ClassNotFoundException: ec.Evolve at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) Could not find the main class: ec.Evolve. Program will exit. I tried even to launch it in the directory where Evolve.class is located. same error. Maybe somebody has very clear in mind where's the problem. thanks.