Hi All, My application is a SWT application on the client side and an EJB3 on JBoss 4.2.2 on the server side. Users(from client) can upload jars containing classes that are copied onto the JBoss server machine to a known directory. The classes within the newly uploaded jars have to be loaded,instantiated and a known method has to be called on them. We have enforced upon the user to implement our base interfaces in their classes so that we can call any new jars that are uploaded at runtime without shutting down and bringing up JBoss. I am getting a NullPointerException when I try to load the class dynamically(using URLClassLoader) We have tried using URLClassLoader but the loaded class is not visible at runtime. Also tried to load class using UnifiedClassLoader3 but am not sure I did the right way. Please suggest the best possible way to do this ASAP. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4262444#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...