I've managed to debug it but I don't know where and what it fails. Moreover I miss some sources. Anyway, here is my whole test application : http://beta.livre-rare-book.net/metadebug.tar.bz2 I've not included the lib dir as it's the one from seam 1.3.0.ALPHA. The app uses DefaultDS Step to reproduce : - just deploy the app - login - go to admin (top-right) - click to users (there must be two) - click on new - valid without filling in the form by clicking on create => no validation, but the above exception. pete.muir > I'll test tomorrow to see if then the validation occur when adding required=true or if it just avoid empty fields. Thanks for your help :) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4056584#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...