I've set up a JBoss AS 5.1 installation of Guvnor (5.3.1 GA) using the JBPM 5.2 installer (installed using the provided ANT script).
After some usage of Guvnor and jbpm-console without apparent issues, jbpm-console becomes unable to communicate with Guvnor.
Snippet of "server.log":
2012-07-11 12:22:47,803 ERROR [STDERR] (http-0.0.0.0-8080-1) java.lang.LinkageError: loader constraint violation: when resolving overridden method "com.sun.xml.bind.v2.runti me.MarshallerImpl.marshal(Ljava/lang/Object;Ljavax/xml/stream/XMLStreamWriter;)V" the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) of the curren t class, com/sun/xml/bind/v2/runtime/MarshallerImpl, and its superclass loader (instance of <bootloader>), have different Class objects for the type javax/xml/stream/XMLStre amWriter used in the signature 2012-07-11 12:22:47,809 ERROR [STDERR] (http-0.0.0.0-8080-1) at com.sun.xml.bind.v2.runtime.JAXBContextImpl.createMarshaller(JAXBContextImpl.java:772) 2012-07-11 12:22:47,809 ERROR [STDERR] (http-0.0.0.0-8080-1) at com.sun.xml.bind.v2.runtime.JAXBContextImpl.createMarshaller(JAXBContextImpl.java:141) ... 012-07-11 12:22:47,825 INFO [STDOUT] (http-0.0.0.0-8080-7) 12:22:47,825 ERROR [GuvnorConnectionUtils] Error retriving packages from guvnor: ParseError at [row,col]:[2,1] Message: XML document structures must start and end within the same entity. 2012-07-11 12:22:47,847 INFO [STDOUT] (http-0.0.0.0-8080-7) 12:22:47,847 INFO [GuvnorConnectionUtils] Did not find process image for: com.sample.evaluation 2012-07-11 12:22:47,847 INFO [STDOUT] (http-0.0.0.0-8080-7) 12:22:47,847 ERROR [GraphViewerPluginImpl] Could not get diagram url from Guvnor: null
Now, since jaxb is part of the JRE since version 1.6.0_04, I guess some other webapp triggered bootloader classloading of MarshallerImpl.
I removed jaxb-impl-220.127.116.11 from the WEB-INF/lib folder of drools-guvnor and now it appears to run without problems.
Wouldn't it be better to remove jaxb-impl from WEB-INF/lib in guvnor distribution wars? Do I miss something?
Thanks in advance, regards.