Hi, I have install the spark client xmpp. I works very well with openfire, but suddenly when I exec spark: [maykel@maykel-arch ~]$ spark Exception in thread "main" java.lang.NoClassDefFoundError: com/install4j/runtime/Launcher Caused by: java.lang.ClassNotFoundException: com.install4j.runtime.Launcher 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: com.install4j.runtime.Launcher. Program will exit. [maykel@maykel-arch ~]$ echo $JAVA_HOME /usr/lib/jvm/jre1.7.0_55 [maykel@maykel-arch ~]$ java -version java version "1.7.0_55" Java(TM) SE Runtime Environment (build 1.7.0_55-b13) Java HotSpot(TM) 64-Bit Server VM (build 24.55-b03, mixed mode) Thanks in advanced.