The stack trace is about launch of a server or java app  - not aobut starting jboss developer studio 5. Could you provide some more details on what you are trying to do ? p.s. may I suggest you use a newer version of JBoss Developer Studio {emoticon:class=jive_macro jive_emote|src=https://community.jboss.org/6.0.3.60ddddd/images/emoticons... Posted by forums Original post: https://community.jboss.org/message/857452#857452