I am getting an error that I'm not sure how to fix. It appears that it happens when the EJB container (i think) tries to passivate one of my EJB 3.0 statefull session beans. The top level exception, and the root cause of the exception are posted below. So basically it looks like somewhere something is trying to use reflection to load the class:org.omg.CORBA.InterfaceDef but it can't be found anywhere. I think this happens when the EJB container tries to passivate one of my statefull session beans. I'd just include the class on my classpath, but I can't even find somewhere to download it from. Top Level Exception 00:53:43,992 ERROR [HoldemTableBean] problem passivation thread javax.ejb.EJBException: Could not passivate; failed to save state at org.jboss.ejb3.cache.simple.StatefulSessionFilePersistenceManager.passivateSession(StatefulSessionFilePersistenceManager.java:409) [Rest of Stack Trace Ommitted] The root cause of the error is this: Caused by: java.lang.ClassNotFoundException: org.omg.CORBA.InterfaceDef from BaseClassLoader@adc928{VFSClassLoaderPolicy@1716fcd{name=vfsfile:/C:/jboss-5.0.1.GA/server/default/deployers/ejb3.deployer/ domain=ClassLoaderDomain@18aecf1{name=DefaultDomain parentPolicy=BEFORE parent=org.jboss.system.NoAnnotationURLClassLoader@4cee32} roots=[MemoryContextHandler@6498190[path= context=vfsmemory://5c4o15i-b318ui-fx2upwhw-1-fx2uq4jy-8 real=vfsmemory://5c4o15i-b318ui-fx2upwhw-1-fx2uq4jy-8], FileHandler(a)28958965[path=ejb3.deployer context=file:/C:/jboss-5.0.1.GA/server/default/deployers/ real=file:/C:/jboss-5.0.1.GA/server/default/deployers/ejb3.deployer/], DelegatingHandler(a)6303790[path=ejb3.deployer/jboss-ejb3-deployer.jar context=file:/C:/jboss-5.0.1.GA/server/default/deployers/ real=file:/C:/jboss-5.0.1.GA/server/default/deployers/ejb3.deployer/jboss-ejb3-deployer.jar], DelegatingHandler(a)16463057[path=ejb3.deployer/jboss-ejb3-iiop.jar context=file:/C:/jboss-5.0.1.GA/server/default/deployers/ real=file:/C:/jboss-5.0.1.GA/server/default/deployers/ejb3.deployer/jboss-ejb3-iiop.jar]] delegates=null exported=[org.jboss.as.javaee, org.jboss.ejb3.clientmodule, org.jboss.ejb3.deployers, org.jboss.ejb3.deployers.tmp, org.jboss.ejb3.iiop, org.jboss.as.jpa.resolvers, META-INF] <IMPORT-ALL>NON_EMPTY}} [Rest of Stack Trace Ommitted] My Environment OS: WIndows Vista 32 bit JBOSS 5.1 Thanks in advance for any help. -Mike View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4243176#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...