I have implemented my own CallbackHandler and in jboss-service.xml have the following: <!-- JAAS security manager and realm mapping --> | <mbean code="org.jboss.security.plugins.JaasSecurityManagerService" | name="jboss.security:service=JaasSecurityManager"> | <attribute name="ServerMode">true</attribute> | <attribute name="SecurityManagerClassName">org.jboss.security.plugins.JaasSecurityManager</attribute> | <attribute name="DefaultUnauthenticatedPrincipal">anonymous</attribute> | <attribute name="CallbackHandlerClassName"> | com.security.auth.module.DbCallbackHandler | </attribute> | <attribute name="DefaultCacheTimeout">1800</attribute> | <attribute name="DefaultCacheResolution">60</attribute> | <attribute name="DeepCopySubjectMode">false</attribute> | </mbean> When I start the server I get the following: [ServiceConfigurator] Problem configuring service jboss.security:service=JaasSecurityManager org.jboss.deployment.DeploymentException: Exception setting attribute javax.management.Attribute@869113 on mbean jboss.security:service=JaasSecurityManager; - nested throwable: (java. ng.ClassNotFoundException: No ClassLoaders found for: com.security.auth.module.DbCallbackHandler) The class file for DbCallbackHandler does exist in one of my deployed project jars. Does the implemented CallbackHandler class need to exist in some other JBoss directory? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4224902#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...