Actually this is happening at the compile stage, but the principle is the same. Solution: Use JDK1.5 compiler, OR use JDK1.4 compiler and remove the JDK 1.5 rt.jar from your classpath. Also, next time you get an error you don't understand, try googling for it first. :) In this case you would have found the solution very quickly....... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3973023#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...