I am currently involved in a migration of web applications from single Jboss 3.2.2 to Jboss 4.2.1 cluster version. I need to deploy an application as a singleton, so I want to deploy it to deploy-hasingleton directory in the all configuration. When the application is deployed in deploy directory, the application runs without problems, like in Jboss 3.2.2. When the application is removed from deploy directory and deployed in deploy-hasingleton directory instead, the application starts up, but when I try to get a html page, I get an error: org.apache.cocoon.ProcessingException: Lookup of serializer for role 'html' failed.: While surfing on the net I came across the problem in http://www.mail-archive.com/users@cocoon.apache.org/msg20943.html. But there is apparently no reply The application uses Cocoon 2.1.3 and I have spent a lot of time trying to figure out what could cause the error. I am about to raise a bug report against Jboss 4.2.1, but would like to see if any one can help me out. Lasse Petersen View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4132262#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...