Thank you, jaikiran! You were almost right: The actual error was that the Item class wasn't mapped, which is what made me use the fully qualified name in the first place. However, note: | String queryString2 = "select itm from green20.demo.items.Item itm"; | does NOT throw any exception or error message AT ALL (also not in server log). Once I replaced the fully qualified name, it showed the correct exception again. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4155809#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...