Seam is fully transactional framework and integration with JBPM 3 doesn't fully respect this. If an exception happens in parsing or evaluating of EL expression specified in JBPM process definition (like in action execution), JBPM context and related dirty operations in JBPM persistence doesn't follow the Seam processes for exception handling - rollback is done on Seam side, but while closing JBPM context, JBPM process is trying to commit dirty state in followed transaction, which Seam opens for post process exception handling and destroying of contexts at HTTP request end lifecycle.

For that case there is requirement on Seam side to close JBPM context while Seam is doing rollback and not later when new transaction is started.

Current Seam handling only catches EL exceptions which is individually handled by JSF on frontend. This is of course bad in case of Seam asynchronous invocation in JBPM process definition, because it is not invoked in JSF context and root exception is swallowed. Related issue for asynchronous processing is JBPAPP-5410.