The following error occurs after a jar file is modified then re-deployed. The error disappears upon restarting JBoss.
17:10:49,775 ERROR [STDERR] javax.jdo.JDOUserException: The given element does not meet the requirements for this field. The container requires that all non-null objects are of the type declared in the XML metadata for this container. "class test.persist.User.isAssignableFrom (class test.persist.User)" failed.
(test.persist.User is an enhanced, persistance-capable class for use with JDO)