NoClassDefFoundError: org/apache/commons/configuration/ConfigurationException

Check if the lib is contained in the lib folder of your app, it might be possible that you left it via packaging via ant or maven. the next probable reason might be that you jar is corrupted. try to decompile and check(though this is very rare).

Allways do remeber classNotFound exception simply means that your program is unable to find concern class for whatsoever reason. add it to your lib/classpath. There is no other reason possible.