gentoo Desktop # java jnetcube.jar Exception in thread "main" java.lang.NoClassDefFoundError: jnetcube/jar gentoo Desktop # java -version java version "1.4.2-03" Java(TM) 2 Runtime Environment, Standard Edition (build Blackdown-1.4.2-03) Java HotSpot(TM) Client VM (build Blackdown-1.4.2-03, mixed mode) gentoo Desktop # java -jar jnetcube.jar Exception in thread "main" java.lang.UnsupportedClassVersionError: Standalone (Unsupported major.minor version 49.0) at java.lang.ClassLoader.defineClass0(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$100(Unknown Source) 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) at java.lang.ClassLoader.loadClassInternal(Unknown Source)