Just in case anyone else is looking at this an wondering what's going on. I had the same issue on JBoss 4.0.5GA. It turned out that under the folder /server//date/hypersonic the files had been corrupted. It seems that normally when you shutdown the server these get cleaned up and when you start the server they are recreated from the configuration. Basically I deleted the hypersonic directory and contents and restarted JBoss and everything sorted itself out. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4068568#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...