title: Strange Play Framework 2.2 exceptions after trying to add MySQL / slick
body: <p>I'm working on a Play 2.2 application, and things have gone a bit south on me since I've tried adding my DB layer.</p>
  
  <p>Below are my <code>build.sbt</code> dependencies. As you can see I use <code>mysql-connector-java</code> and <code>play-slick</code>:</p>
  
  <pre><code>libraryDependencies ++= Seq(
    jdbc,
    anorm,
    cache,
    "joda-time" % "joda-time" % "2.3",
    "mysql" % "mysql-connector-java" % "5.1.26",
    "com.typesafe.play" %% "play-slick" % "0.5.0.8",
    "com.aetrion.flickr" % "flickrapi" % "1.1"
  )
  </code></pre>
  
  <p>My <code>application.conf</code> has some similarly simple DB stuff in it:</p>
  
  <pre><code>db.default.url="jdbc:mysql://localhost/myDb"
  db.default.driver="com.mysql.jdbc.Driver"
  db.default.user="root"
  db.default.pass=""
  </code></pre>
  
  <p>This is what it looks like when my Play server starts:</p>
  
  <pre><code>[info] play - Listening for HTTP on /0:0:0:0:0:0:0:0:9000
  
  (Server started, use Ctrl+D to stop and go back to the console...)
  
  [info] Compiling 1 Scala source to C:\bbq\cats\in\space
  [info] play - database [default] connected at jdbc:mysql://localhost/myDb
  [info] play - Application started (Dev)
  </code></pre>
  
  <p>So, it appears that Play can connect to the MySQL DB just fine (I think). However, I get this exception when I make any request to my server:</p>
  
  <pre><code>[error] p.nettyException - Exception caught in Netty
  java.lang.NoSuchMethodError: akka.actor.ActorSystem.dispatcher()Lscala/concurren
  t/ExecutionContext;
          at play.core.Invoker$.&lt;init&gt;(Invoker.scala:24) ~[play_2.10.jar:2.2.0]
          at play.core.Invoker$.&lt;clinit&gt;(Invoker.scala) ~[play_2.10.jar:2.2.0]
          at play.api.libs.concurrent.Execution$Implicits$.defaultContext$lzycompu
  te(Execution.scala:7) ~[play_2.10.jar:2.2.0]
          at play.api.libs.concurrent.Execution$Implicits$.defaultContext(Executio
  n.scala:6) ~[play_2.10.jar:2.2.0]
          at play.api.libs.concurrent.Execution$.&lt;init&gt;(Execution.scala:10) ~[play
  _2.10.jar:2.2.0]
          at play.api.libs.concurrent.Execution$.&lt;clinit&gt;(Execution.scala) ~[play_
  2.10.jar:2.2.0]
  </code></pre>
  
  <p>The odd thing is that the 2nd request (to the exact same URL, same controller, no changes) comes back with a different error:</p>
  
  <pre><code>[error] p.nettyException - Exception caught in Netty
  java.lang.NoClassDefFoundError: Could not initialize class play.api.libs.concurr
  ent.Execution$
          at play.core.server.netty.PlayDefaultUpstreamHandler.handleAction$1(Play
  DefaultUpstreamHandler.scala:194) ~[play_2.10.jar:2.2.0]
          at play.core.server.netty.PlayDefaultUpstreamHandler.messageReceived(Pla
  yDefaultUpstreamHandler.scala:169) ~[play_2.10.jar:2.2.0]
          at com.typesafe.netty.http.pipelining.HttpPipeliningHandler.messageRecei
  ved(HttpPipeliningHandler.java:62) ~[netty-http-pipelining.jar:na]
          at org.jboss.netty.handler.codec.http.HttpContentDecoder.messageReceived
  (HttpContentDecoder.java:108) ~[netty-3.6.5.Final.jar:na]
          at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:29
  6) ~[netty-3.6.5.Final.jar:na]
          at org.jboss.netty.handler.codec.frame.FrameDecoder.unfoldAndFireMessage
  Received(FrameDecoder.java:459) ~[netty-3.6.5.Final.jar:na]
  </code></pre>
  
  <p>The URL / controller that I'm requesting just renders a static web page and doesn't do anything of any significance. It was working just fine before I started adding my DB layer. <a href="http://i.imgur.com/SvmJcNv.jpg" rel="nofollow">I'm rather stuck.</a> Any help would be greatly appreciated, thanks.</p>
  
  <p>I'm using Scala 2.10.2, Play 2.2.0, and MySQL Server 5.6.14.0 (community edition).</p>