Hi, I have an application that works fine on JBoss when the jar files are deployed separately but throws a NoClassDefFoundError when they are deployed in a .ear file together. I studied the FAQ about this topic and I know the Class-Path manifest header but I was not able to solve my problem. I describe the content of my ear file and the references between them. | application.ear | framework.jar | (EJB Module, contains the remove interfaces too). | Class-Path: plugin1.jar plugin2.jar framework.jar | plugin1.jar | (Utility classes) | Class-Path: business-logic.jar | plugin2.jar | (Utility classes) | Class-Path: business-logic.jar | business-logic.jar | (Utility classes) | Class-Path: framework.jar | As you can see there are circular references between the jar files (i.e framework.jar - plugin1.jar - business-logic.jar - framework.jar). I suspect this could be the cause of the problem. Even an EJB module participates in a circle. Does the J2EE standard allow such circular references between the jar files in an ear file? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3979695#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...