If a class cannot be deserialized safely, try to fallback and use the XARecoveryModule to locate an appropriate XAResource -------------------------------------------------------------------------------------------------------------------------- Key: JBTM-2550 URL: https://issues.jboss.org/browse/JBTM-2550 Project: JBoss Transaction Manager Issue Type: Enhancement Components: Recovery Affects Versions: 5.2.8.Final Reporter: Amos Feng Assignee: Tom Jenkinson Priority: Blocker Fix For: 4.17.33, 5.2.10.Final This exception happens with using the IBM MQ rar in the wildfly. com.ibm.mq.connector.xa.XARWrapper is the serialize object. when the RecoveryManager tries to restore_state from the object record, it will load the class and threw CNFE as it can not access the XARWrapper classe in the RAR We can catch this exception and try to get from the helpers.