Two things to try. In Eclipse, In the Package Explorer, when you expand your project there should be an entry for "JRE System Library" with a version in brackets behind it. What is that version? %java_home%\bin\javap -verbose -classpath xxx com.demo.hello.HelloBeanBean where xxx is the base directory into which Eclipse is compiling the classes. Post the output. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4172876#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...