01:25:18,800 PM [testsystem-pekko.actor.default-dispatcher-5] [INFO] Slf4jLogger - Slf4jLogger started 01:25:19,104 PM [testsystem-pekko.actor.default-dispatcher-6] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason] 01:25:19,108 PM [testsystem-pekko.actor.default-dispatcher-6] [INFO] RepointableActorRef - pekkoDeadLetter Message [java.lang.String] from Actor[pekko://testsystem/system/testActor-13#-1256958400] to Actor[pekko://testsystem/user/pingpongactor#1550717939] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[pekko://testsystem/user/pingpongactor#1550717939] may have terminated unexpectedly. This logging can be turned off or adjusted with configuration settings 'pekko.log-dead-letters' and 'pekko.log-dead-letters-during-shutdown'.