2019-04-15 21:15:11,750 WARN  [org.apache.activemq.artemis.core.message.impl.CoreMessage] (Thread-1884 (ActiveMQ-server-org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl$5@2a079d8a)) Error creating String for message: : java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1442) [rt.jar:1.8.0_172]
	at java.util.HashMap$EntryIterator.next(HashMap.java:1476) [rt.jar:1.8.0_172]
	at java.util.HashMap$EntryIterator.next(HashMap.java:1474) [rt.jar:1.8.0_172]
	at org.apache.activemq.artemis.utils.collections.TypedProperties.toString(TypedProperties.java:464) [artemis-commons-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at java.lang.String.valueOf(String.java:2994) [rt.jar:1.8.0_172]
	at java.lang.StringBuilder.append(StringBuilder.java:131) [rt.jar:1.8.0_172]
	at org.apache.activemq.artemis.core.message.impl.CoreMessage.toString(CoreMessage.java:1200) [artemis-core-client-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at java.lang.String.valueOf(String.java:2994) [rt.jar:1.8.0_172]
	at java.lang.StringBuilder.append(StringBuilder.java:131) [rt.jar:1.8.0_172]
	at org.apache.activemq.artemis.core.server.impl.MessageReferenceImpl.toString(MessageReferenceImpl.java:246) [artemis-server-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at java.lang.String.valueOf(String.java:2994) [rt.jar:1.8.0_172]
	at java.lang.StringBuilder.append(StringBuilder.java:131) [rt.jar:1.8.0_172]
	at org.apache.activemq.artemis.core.server.impl.ServerConsumerImpl.handle(ServerConsumerImpl.java:398) [artemis-server-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.core.server.impl.QueueImpl.handle(QueueImpl.java:2983) [artemis-server-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.core.server.impl.QueueImpl.deliver(QueueImpl.java:2334) [artemis-server-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.core.server.impl.QueueImpl.access$2000(QueueImpl.java:107) [artemis-server-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.core.server.impl.QueueImpl$DeliverRunner.run(QueueImpl.java:3209) [artemis-server-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:42) [artemis-commons-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:31) [artemis-commons-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at org.apache.activemq.artemis.utils.actors.ProcessorBase.executePendingTasks(ProcessorBase.java:66) [artemis-commons-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [rt.jar:1.8.0_172]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [rt.jar:1.8.0_172]
	at org.apache.activemq.artemis.utils.ActiveMQThreadFactory$1.run(ActiveMQThreadFactory.java:118) [artemis-commons-2.6.3.redhat-00014.jar:2.6.3.redhat-00014]