From the error, it is still evident that we have a reference for "http://java.sun.com/xml/ns/j2ee" in application.xml.
Try removing all the references of the xmlns element from the application.xml.
It should look like below.
<application>
<display-name>TechConf</display-name>
<description>TechConf
J2EE Application</description>
........
Regards,
Anadraj
http://weblogic-wonders.com