I just had the same problem in Ubuntu 14.04 trying to build the zentask sample app. I eliminated the offending line in the build.sbt and added play.Project.playScalaSettings
to the end and was able to compile and run from the Play console. This is my current zentask build.sbt (empty lines are needed):
name := "zentask"
version := "1.0"
libraryDependencies ++= Seq(jdbc, anorm)
scalaVersion := Option(System.getProperty("scala.version")).getOrElse("2.10.4")
play.Project.playScalaSettings