Exception in thread "main" java.lang.NoSuchMethodError: scala.collection.immutable.HashSet$.empty()Lscala/collection/immutable/HashSet;
at akka.actor.ActorCell$.<init>(ActorCell.scala:336)
at akka.actor.ActorCell$.<clinit>(ActorCell.scala)
at akka.actor.RootActorPath.$div(ActorPath.scala:159)
at akka.actor.LocalActorRefProvider.<init>(ActorRefProvider.scala:464)
at akka.actor.LocalActorRefProvider.<init>(ActorRefProvider.scala:452)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at akka.actor.ReflectiveDynamicAccess$$anonfun$createInstanceFor$2.apply(DynamicAccess.scala:78)
at scala.util.Try$.apply(Try.scala:191)
at akka.actor.ReflectiveDynamicAccess.createInstanceFor(DynamicAccess.scala:73)
at akka.actor.ReflectiveDynamicAccess$$anonfun$createInstanceFor$3.apply(DynamicAccess.scala:84)
at akka.actor.ReflectiveDynamicAccess$$anonfun$createInstanceFor$3.apply(DynamicAccess.scala:84)
at scala.util.Success.flatMap(Try.scala:230)
at akka.actor.ReflectiveDynamicAccess.createInstanceFor(DynamicAccess.scala:84)
at akka.actor.ActorSystemImpl.liftedTree1$1(ActorSystem.scala:584)
at akka.actor.ActorSystemImpl.<init>(ActorSystem.scala:577)
at akka.actor.ActorSystem$.apply(ActorSystem.scala:141)
at akka.actor.ActorSystem$.apply(ActorSystem.scala:108)
at akka.Akka$.delayedEndpoint$akka$Akka$1(Akka.scala:11)
at akka.Akka$delayedInit$body.apply(Akka.scala:9)
at scala.Function0$class.apply$mcV$sp(Function0.scala:40)
at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
at scala.App$$anonfun$main$1.apply(App.scala:76)
at scala.App$$anonfun$main$1.apply(App.scala:76)
at scala.collection.immutable.List.foreach(List.scala:383)
at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35)
at scala.App$class.main(App.scala:76)
at akka.Akka$.main(Akka.scala:9)
at akka.Akka.main(Akka.scala)

解决办法：将scala2.11换成scala2.10