problem with eclipse and lomboz

I integrated lomboz into eclipse and used lomboz to create a j2ee project which inclue a web module. when i clicked "run server", i got some error hints as follow:
Error occurred during initialization of VM
java/lang/NoClassDefFoundError: java/lang/Object
who can tell me why?
thanks in advance.

It's a common problem - normally because of you must be having a missing "JRE System Library" in your project settings (Project -> settings -> Java build path- > Libraries).