I was using JDK 1.5.0_05. I upgraded to JDK 1.5.0_07 and I hit the IncompatibleClassException. It looks like they changed the behavior at some release after JDK 1.5.0_05. A note in the javax.xml.namespace.QName source code explains: anonymous wrote : * Due to a historical defect, QName was released with multiple | * serialVersionUID values even though its serialization was the | * same. | * | * To workaround this issue, serialVersionUID is set with either | * a default value or a compatibility value. To use the | * compatiblity value, set the system property: | * | * com.sun.xml.namespace.QName.useCompatibleSerialVersionUID=1.0. Running the tests with the aforementioned system property set fixes the incompatibility problem: - Set the ANT_OPTS environment property to -Dcom.sun.xml.namespace.QName.useCompatibleSerialVersionUID=1.0 so that the ant batch file/shell script passes the system property to the JVM. - Execute target run-test. You will notice JBossWS requires some Xerces class not included in the JDK, so you still need Xerces on the classpath. - Replace BPEL_HOME/doc/examples/process.template.xml with the file attached to the jBPM BPEL beta 1 addendum wiki page. - Execute run-test again. It should work this time. Alternatively, you can use the endorsed standards override mechanism. Endorsing seems easier than the above procedure. I will recommend endorsing in future BPEL releases. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3961444#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...