We are migrating one of our projects to jboss 4.2.0GA. After identifying that we also have to copy commons-digester*.jar and commons-beanutils*.jar to WEB-INF/lib folder there are no more errors at startup. But we get the org.apache.commons.collections.UnboundedFifoBuffer error:-( We have replaced the commons-collection.jar in jboss*/server/default/lib with one of the versions comming from seam-gen(seam1.2.1GA) And we are also copying commons-beanutils (in this case version 1.7) Situation: 1.) Having a project generated with seam-gen(from Seam1.2.1GA) running on JBoss AS 4.0.5GA without complains 2.) Using the instructions on this site: [url]http://www.michaelyuan.com/blog/2007/05/29/seam-book-examples-updated... [/url] we tried to migrate to JBoss AS 4.2.0GA 3.) Making the changes corresponding to beanutils and digester 4.) Server starts fine and we are getting the UnboundedFifoBuffer error 5.) Googeling about this error finding among other posts this thread. 6.) trying to copy the right versions of collection and digester.jars 7.) Stuck.. No solution so i post here. Can one post me a link to working versions of the librarys. We do have seam-1.2.1GA richfaces-1.1.1 with corresponding Ajax facelets 1.0.13 alpha commons-collections3.1 (from generated app) commons-digester1.6 commons-beanutils-1.7.0 Hope someone can help me out. Ciao, baz View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4055525#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...