idea運行akka第一個例子出錯

import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props
class HelloActor extends Actor {
  def receive = {
    case "hello" => println("您好！")
    case _ => println("您是?")
  }
}
object Main extends App {
  val system = ActorSystem("HelloSystem")
  // 缺省的Actor構造函數
  val helloActor = system.actorOf(Props[HelloActor], name = "helloactor")
  helloActor ! "hello"
  helloActor ! "喂"
}

運行時出現錯誤提示：scala.Predef$.refArrayOps([Ljava/lang/Object;)Lscala/collection/mutable/ArrayOps

個人系統scala版本是2.12(而且在idea的project settings--libraries中增長的是com_typesafe_akka_akka_actor_2_12_0_M1_2_4_M2庫)，根據網上有人寫的提示做以下修改：

將scala-sdk從2.12換爲2.11

File -> Project Structure -> Global libraries -> Remove SDK -> Rebuild.

最終成功了。