What I have found is that by adding the AOP nature to the eclipse project, the builder gets added, and then automatic AOPC works great from there on. However, the AOP nature brings with it the above problem each and every time file is opened for editing, or an editor tab is chosen to edit a different source file. The above exception is immediately thrown, and an eclipse message pops up asking you to check the error log. Thank you. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4091218#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...