I'm facing this problem but I'm not sure where or when it occurs. It seems to be randomly. The virtual procedure that is run while this problem occurs, copies data from one xa-datasource to a temp table and then inserts it into a non-xa datasource.

2018-10-22 09:50:28,361 WARN [org.teiid.PROCESSOR] (Worker25_QueryProcessorQueue73179) F274YMAVci29 TEIID31200 Lower level transaction Local transaction (delegate=TransactionImple < ac, BasicAction: 0:ffffac130002:-2cc3b1fb:5bcd8cc9:f717 status: ActionStatus.RUNNING >, owner=Local transaction context for provider JBoss JTA transaction provider) not properly ended, rolling back.
2018-10-22 09:50:28,361 WARN [org.teiid.PROCESSOR] (Worker25_QueryProcessorQueue73179) F274YMAVci29 TEIID30028 Failed to properly rollback autowrap transaction properly: org.teiid.client.xa.XATransactionException: TEIID30535 java.lang.IllegalStateException: No transaction associated with the current thread
at org.teiid.dqp.internal.process.TransactionServerImpl.rollbackDirect(TransactionServerImpl.java:432)
at org.teiid.dqp.internal.process.TransactionServerImpl.rollback(TransactionServerImpl.java:551)
at sun.reflect.GeneratedMethodAccessor127.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.teiid.logging.LogManager$LoggingProxy.invoke(LogManager.java:117)
at com.sun.proxy.$Proxy25.rollback(Unknown Source)
at org.teiid.dqp.internal.process.RequestWorkItem.close(RequestWorkItem.java:574)
at org.teiid.dqp.internal.process.RequestWorkItem.process(RequestWorkItem.java:375)
at org.teiid.dqp.internal.process.AbstractWorkItem.run(AbstractWorkItem.java:47)
at org.teiid.dqp.internal.process.RequestWorkItem.run(RequestWorkItem.java:276)
at org.teiid.dqp.internal.process.DQPWorkContext.runInContext(DQPWorkContext.java:277)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$RunnableWrapper.run(ThreadReuseExecutor.java:115)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$3.run(ThreadReuseExecutor.java:206)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalStateException: No transaction associated with the current thread
at org.wildfly.transaction.client.ContextTransactionManager.rollback(ContextTransactionManager.java:81)
at org.teiid.dqp.internal.process.TransactionServerImpl.rollbackDirect(TransactionServerImpl.java:426)
... 16 more

2018-10-22 09:50:28,389 WARN [org.teiid.PROCESSOR] (Worker22_QueryProcessorQueue73181) F274YMAVci29 TEIID30020 Processing exception for request F274YMAVci29.39 'TEIID30538 java.lang.IllegalStateException: WFTXN0007: A transaction is already associated with the current thread'. Originally XATransactionException ContextTransactionManager.java:140. Enable more detailed logging to see the entire stacktrace.