Play Framework and Eclipse: java.lang.NoClassDefFoundError: controllers/routes - eclipse

Question

I created a new application using the command
activator new myapp play-java
Then, without modifying anything, I used
activator ui
For opening the admin web console of the new project. Then, I generated the eclipse project of my application from that console. Then I imported the project into a new eclipse workspace and it was good, but when I did run the IntegrationTest class (right click on the file) I got this exception:
[ERROR] [09/03/2014 17:50:25.444] [play-akka.actor.default-dispatcher-3] [ActorSystem(play)] Uncaught error from thread [play-akka.actor.default-dispatcher-3] shutting down JVM since 'akka.jvm-exit-on-fatal-error' is enabled
java.lang.NoClassDefFoundError: controllers/routes
at views.html.main$.apply(main.template.scala:36)
at views.html.index$.apply(index.template.scala:31)
at views.html.index$.render(index.template.scala:39)
at views.html.index.render(index.template.scala)
at controllers.Application.index(Application.java:11)
at Routes$$anonfun$routes$1$$anonfun$applyOrElse$1$$anonfun$apply$1.apply(routes_routing.scala:59)
at Routes$$anonfun$routes$1$$anonfun$applyOrElse$1$$anonfun$apply$1.apply(routes_routing.scala:59)
at play.core.Router$HandlerInvokerFactory$$anon$4.resultCall(Router.scala:264)
at play.core.Router$HandlerInvokerFactory$JavaActionInvokerFactory$$anon$15$$anon$1.invocation(Router.scala:255)
at play.core.j.JavaAction$$anon$1.call(JavaAction.scala:55)
at play.core.j.JavaAction$$anonfun$11.apply(JavaAction.scala:82)
at play.core.j.JavaAction$$anonfun$11.apply(JavaAction.scala:82)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at play.core.j.HttpExecutionContext$$anon$2.run(HttpExecutionContext.scala:40)
at play.api.libs.iteratee.Execution$trampoline$.execute(Execution.scala:46)
at play.core.j.HttpExecutionContext.execute(HttpExecutionContext.scala:32)
at scala.concurrent.impl.Future$.apply(Future.scala:31)
at scala.concurrent.Future$.apply(Future.scala:492)
at play.core.j.JavaAction$class.apply(JavaAction.scala:82)
at play.core.Router$HandlerInvokerFactory$JavaActionInvokerFactory$$anon$15$$anon$1.apply(Router.scala:252)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:130)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:130)
at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:129)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:128)
at scala.Option.map(Option.scala:145)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:128)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:121)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:483)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:483)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:519)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:519)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$14.apply(Iteratee.scala:496)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$14.apply(Iteratee.scala:496)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:41)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.lang.ClassNotFoundException: controllers.routes
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 43 more
Somebody knows how do I fix that?
Thanks a lot !

Answer 1

Most likely caused by Eclipse running sbt to build the workspace concurrently with activator. This thread has an in-depth explanation. Try turning off "Build Automatically" in Eclipse, or instruct it to build to a different directory than target.