The server returns the following XA exception:
WARN [com.arjuna.ats.jta.logging.loggerI18N] [com.arjuna.ats.internal.jta.recovery.xarecovery1] Local XARecoveryModule.xaRecovery got XA exception javax.transaction.xa.XAException, XAException.XAER_RMERR
To remedy the situation, do the following:
GRANT SELECT ON sys.dba_pending_transactions TO user;
GRANT SELECT ON sys.pending_trans$ TO user;
GRANT SELECT ON sys.dba_2pc_pending TO user;
GRANT EXECUTE ON sys.dbms_xa TO user;
The above assumes that the user is the user defined to connect from WildFly to Oracle. It also assumes that either Oracle 10g R2 (patched for bug 5945463) or 11g is used. If an unpatched version, that is, a version older that 11g, is used, change the last GRANT EXECUTE to the following:
GRANT EXECUTE ON sys.dbms_system TO user;