Hi all, I tried to deploy the EJB application on the jboss 5 which was working on jboss 4. the Deployment failed and throw an exception 11:19:01,625 ERROR [AbstractKernelController] Error installing to PostClassLoader: name=vfszip:/D:/SERD/servers/jboss-5. 1.0.GA/server/default/deploy/plm-publish.ear/ state=ClassLoader mode=Manual requiredState=PostClassLoader org.jboss.deployers.spi.DeploymentException: Cannot process metadata at org.jboss.deployers.spi.DeploymentException.rethrowAsDeploymentException(DeploymentException.java:49) at org.jboss.deployment.AnnotationMetaDataDeployer.deploy(AnnotationMetaDataDeployer.java:181) at org.jboss.deployment.AnnotationMetaDataDeployer.deploy(AnnotationMetaDataDeployer.java:93) at org.jboss.deployers.plugins.deployers.DeployerWrapper.deploy(DeployerWrapper.java:171) at org.jboss.deployers.plugins.deployers.DeployersImpl.doDeploy(DeployersImpl.java:1439) at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1157) at org.jboss.deployers.plugins.deployers.DeployersImpl.install(DeployersImpl.java:1098) at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:348) at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631) at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553) at org.jboss.deployers.plugins.deployers.DeployersImpl.process(DeployersImpl.java:781) at org.jboss.deployers.plugins.main.MainDeployerImpl.process(MainDeployerImpl.java:702) at org.jboss.system.server.profileservice.repository.MainDeployerAdapter.process(MainDeployerAdapter.java:117) at org.jboss.system.server.profileservice.repository.ProfileDeployAction.install(ProfileDeployAction.java:70) at org.jboss.system.server.profileservice.repository.AbstractProfileAction.install(AbstractProfileAction.java:53 ) at org.jboss.system.server.profileservice.repository.AbstractProfileService.install(AbstractProfileService.java: 361) at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:348) at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631) at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553) at org.jboss.system.server.profileservice.repository.AbstractProfileService.activateProfile(AbstractProfileServi ce.java:306) at org.jboss.system.server.profileservice.ProfileServiceBootstrap.start(ProfileServiceBootstrap.java:271) at org.jboss.bootstrap.AbstractServerImpl.start(AbstractServerImpl.java:461) at org.jboss.Main.boot(Main.java:221) at org.jboss.Main$1.run(Main.java:556) at java.lang.Thread.run(Thread.java:619) Caused by: java.lang.ClassNotFoundException: Empty class name '' at org.jboss.classloader.plugins.ClassLoaderUtils.checkClassName(ClassLoaderUtils.java:52) at org.jboss.classloader.spi.base.BaseClassLoader.loadClass(BaseClassLoader.java:416) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at org.jboss.deployment.OptAnnotationMetaDataDeployer.processJBossClientMetaData(OptAnnotationMetaDataDeployer.j ava:115) at org.jboss.deployment.OptAnnotationMetaDataDeployer.processMetaData(OptAnnotationMetaDataDeployer.java:82) at org.jboss.deployment.AnnotationMetaDataDeployer.deploy(AnnotationMetaDataDeployer.java:177) ... 31 more my envirnoment configuration are JDK 1.6, JBoss 5.1.0 GA, windows Its urgent. Could any body help me in fixing this issue? thank you, Dileep. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4252736#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...