Nobody knows where can the problem for the exception java.lang.NoSuchMethodException: notifyObservers ? I think it could be eventualy one library is needed .. Resume of what have been done : 1 - annotation on POJO 2 - xml file for create MBean cache with cacheloader in /deploy 3 - use of cache in java code 4 - creation of jboss-aop.xml for annotation in /deploy 5 - creation of jboss-aop.xml for preparing POJO in meta-inf of EAR 6 - ant task for aopc the POJOs 7 - replace of AOP 1.5.1 by 1.5.2 on my Jboss 4.0.5 AS 8 - put library of JBossCache 1.4.1 SP3 in Jboss lib 9 - run and crash .. :) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4110932#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...