"paulhuemer" wrote : I am currently migrating existing web projects from JBoss AS 4.0.3 to 4.3.2. | Our web projects utilize Spring 2.5.6.SEC01 and offer WebServices using Apache CXF 2.2.3. | As far as I know, the CXF Stack utilizes Spring 2.5.5 components. Could this cause the problems? Using Spring 2.5.5 in the web application does not change anything. Thanks for your clear information. The Spring 2.5.6.SEC01 in your war file cause this problem . Try to set the classloading isolation in the jboss-web.xml and look at if cxf can work with Spring 2.5.6 SEC01. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4264947#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...