Greg Zoller [http://community.jboss.org/people/gwzoller] replied to the discussion "How to share additional libraries, Jboss 5.1.0GA?" To view the discussion, visit: http://community.jboss.org/message/556350#556350 -------------------------------------------------------------- I hope you find the answer (and post it if you do!). I'm having exactly the same problem and am completely stuck. Some common jars are absolutely fine when I put them in default/lib.  Others blow up exactly how you're describing.  Not sure why but like you I'd really like to get these jars out of my EAR files and into a common lib dir. -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/556350#556350] Start a new discussion in Beginner's Corner at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]