我是lagom scala的新手。创建了一个简单的crud来学习它的关键概念。首先我使用sbt clean compile编译了我的代码，它成功编译了代码。之后我尝试使用sbt clean runAll命令运行项目。有时服务启动时没有任何问题。但有时我发现一条消息说

java.util.concurrent.TimeoutException: The first element has not yet passed through in 5000 milliseconds.
    at akka.stream.impl.Timers$Initial$$anon$1.onTimer(Timers.scala:62)
    at akka.stream.stage.TimerGraphStageLogic.onInternalTimer(GraphStage.scala:1601)
    at akka.stream.stage.TimerGraphStageLogic.$anonfun$getTimerAsyncCallback$1(GraphStage.scala:1590)
    at akka.stream.stage.TimerGraphStageLogic.$anonfun$getTimerAsyncCallback$1$adapted(GraphStage.scala:1590)
    at akka.stream.impl.fusing.GraphInterpreter.runAsyncInput(GraphInterpreter.scala:466)
    at akka.stream.impl.fusing.GraphInterpreterShell$AsyncInput.execute(ActorGraphInterpreter.scala:497)
    at akka.stream.impl.fusing.GraphInterpreterShell.processEvent(ActorGraphInterpreter.scala:599)
    at akka.stream.impl.fusing.ActorGraphInterpreter.akka$stream$impl$fusing$ActorGraphInterpreter$$processEvent(ActorGraphInterpreter.scala:768)
    at akka.stream.impl.fusing.ActorGraphInterpreter$$anonfun$receive$1.applyOrElse(ActorGraphInterpreter.scala:783)
    at akka.actor.Actor.aroundReceive(Actor.scala:534)
    at akka.actor.Actor.aroundReceive$(Actor.scala:532)
    at akka.stream.impl.fusing.ActorGraphInterpreter.aroundReceive(ActorGraphInterpreter.scala:690)
    at akka.actor.ActorCell.receiveMessage(ActorCell.scala:573)
    at akka.actor.ActorCell.invoke(ActorCell.scala:543)
    at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:269)
    at akka.dispatch.Mailbox.run(Mailbox.scala:230)
    at akka.dispatch.Mailbox.exec(Mailbox.scala:242)
    at java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
    at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(Unknown Source)
    at java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
    at java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)

有谁能给我解释一下解决方案吗？提前感谢