Issue Resolved. The reason why I was getting this error was not not because isolation was turned on, it was because the servlets in my WAR file were loading on startup and they referenced classes that existed in the EAR file. Since the WAR and EAR were deployed seperately, the WAR was being loaded before the EAR file and therefore the classes were not found. The solution was to fix the deployment order so that the EAR file was loaded before the WAR file and this was done by updating the \conf\xmdesc\org.jboss.deployment.MainDeployer-xmbean.xml file. The following is the line I changed: <value value="250:.rar,300:-ds.xml,400:.jar,500:.ear,550:.jse,650:.war,800:.bsh"/> As you can see, ear now comes before war. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4171762#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...