Q: When login, I got the following exception:
   java.lang.NoClassDefFoundError
   at com.websina.bean.Person.login(Person.java)

A: This is a very misleading error. The real cause of this is the log file 
   bugzero.log is not writable (.../bugzero/WEB-INF/classes/log/bugzero.log).
   This happens only on Unix/Linux OS where the owner of the application server
   process is different from the log file owner. You need make this file writable to
   this process owner and restart server.

   Before you get this error, when you first time log on to Bugzero from the
   browser, you should get something like:
   java.lang.ExceptionInInitializerError: java.lang.RuntimeException: 
   .....log/bugzero.log (Access is denied)
   at com.websina.util.log.Log.(Log.java) .....

   and subsequent login results NoClassDefFoundError. 


Note: This ExceptionInInitializerError (caused by java.security.AccessControlException)
      and subsequent NoClassDefFoundError also occurred in a restricted hosting environment.

      These issues have since been fixed or handled with a more proper message logged.