02:33:32,648 AM [testsystem-pekko.actor.default-dispatcher-5] [INFO] Slf4jLogger - Slf4jLogger started 02:33:32,994 AM [testsystem-pekko.actor.default-dispatcher-6] [INFO] RepointableActorRef - pekkoDeadLetter Message [java.lang.String] from Actor[pekko://testsystem/system/testActor-30#1765969914] to Actor[pekko://testsystem/user/pingpongactor#2031899153] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[pekko://testsystem/user/pingpongactor#2031899153] 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'.