Why does sbt report "value enablePlugins is not a member of sbt.Project" in Play project?

Question

I've just been getting the following error when trying to compile any Play applications:

error: value enablePlugins is not a member of sbt.Project
lazy val root = (project in file(".")).enablePlugins(PlayScala)
                                       ^
sbt.compiler.EvalException: Type error in expression
    at sbt.compiler.Eval.checkError(Eval.scala:343)
    at sbt.compiler.Eval.compileAndLoad(Eval.scala:165)
    at sbt.compiler.Eval.evalCommon(Eval.scala:135)
    at sbt.compiler.Eval.evalDefinitions(Eval.scala:109)
     ...
     ...
   sbt.compiler.EvalException: Type error in expression
Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore?
Failed to reload source file list: sbt process never got in touch, 
so unable to handle request WatchTransitiveSourcesRequest(true)

I've seen some talk of this error elsewhere but unlike in those examples I don't have any extra plugins or project dependencies- I get this error when compiling an untouched play-scala template after selecting it with activator new.

Here are those plugins included in the template in project/plugins.sbt:

resolvers += "Typesafe repository" at "http://repo.typesafe.com/typesafe/releases/"

// The Play plugin
addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.3.3")

// web plugins
addSbtPlugin("com.typesafe.sbt" % "sbt-coffeescript" % "1.0.0")
addSbtPlugin("com.typesafe.sbt" % "sbt-less" % "1.0.0")
addSbtPlugin("com.typesafe.sbt" % "sbt-jshint" % "1.0.1")
addSbtPlugin("com.typesafe.sbt" % "sbt-rjs" % "1.0.1")
addSbtPlugin("com.typesafe.sbt" % "sbt-digest" % "1.0.0")
addSbtPlugin("com.typesafe.sbt" % "sbt-mocha" % "1.0.0")

The last time I built a Play application was about a month ago and I had no problem, in the meantime I've been compiling vanilla Scala-only apps (often with Activator) without any trouble. Could this be Play-2.3 related?

I have the line sbt.version=0.13.5 in project/build.properties and I've made sure my sbt version is the latest.

My code is exactly that of the play-scala template but in case it makes things easier, here's the contents of build.sbt:

name := """my-first-app"""

version := "1.0-SNAPSHOT"

lazy val root = (project in file(".")).enablePlugins(PlayScala)

scalaVersion := "2.11.1"

libraryDependencies ++= Seq(
  jdbc,
  anorm,
  cache,
  ws
)

Thanks in advance for any help.

EDIT:

Doing sbt about from the app root directory I get this error which I'll include in full:

$ sbt about
[info] Loading global plugins from /home/.sbt/0.13/plugins
[info] Loading project definition from /home/my-first-app/project
/home/my-first-app/build.sbt:5: error: value enablePlugins is not a member of sbt.Project
lazy val root = (project in file(".")).enablePlugins(PlayScala)
                                       ^
sbt.compiler.EvalException: Type error in expression
    at sbt.compiler.Eval.checkError(Eval.scala:343)
    at sbt.compiler.Eval.compileAndLoad(Eval.scala:165)
    at sbt.compiler.Eval.evalCommon(Eval.scala:135)
    at sbt.compiler.Eval.evalDefinitions(Eval.scala:109)
    at sbt.EvaluateConfigurations$.evaluateDefinitions(EvaluateConfigurations.scala:197)
    at sbt.EvaluateConfigurations$.evaluateSbtFile(EvaluateConfigurations.scala:99)
    at sbt.Load$.sbt$Load$$loadSettingsFile$1(Load.scala:507)
    at sbt.Load$$anonfun$sbt$Load$$memoLoadSettingsFile$1$1.apply(Load.scala:502)
    at sbt.Load$$anonfun$sbt$Load$$memoLoadSettingsFile$1$1.apply(Load.scala:501)
    at scala.Option.getOrElse(Option.scala:120)
    at sbt.Load$.sbt$Load$$memoLoadSettingsFile$1(Load.scala:501)
    at sbt.Load$$anonfun$loadSettings$1$2.apply(Load.scala:500)
    at sbt.Load$$anonfun$loadSettings$1$2.apply(Load.scala:500)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
    at scala.collection.AbstractTraversable.map(Traversable.scala:105)
    at sbt.Load$.loadSettings$1(Load.scala:500)
    at sbt.Load$.sbt$Load$$expand$1(Load.scala:523)
    at sbt.Load$.loadSettings(Load.scala:528)
    at sbt.Load$.sbt$Load$$loadSbtFiles$1(Load.scala:464)
    at sbt.Load$.defaultLoad$1(Load.scala:475)
    at sbt.Load$.loadTransitive(Load.scala:478)
    at sbt.Load$.loadProjects$1(Load.scala:418)
    at sbt.Load$.loadUnit(Load.scala:419)
    at sbt.Load$$anonfun$15$$anonfun$apply$11.apply(Load.scala:256)
    at sbt.Load$$anonfun$15$$anonfun$apply$11.apply(Load.scala:256)
    at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:93)
    at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:92)
    at sbt.BuildLoader.apply(BuildLoader.scala:143)
    at sbt.Load$.loadAll(Load.scala:312)
    at sbt.Load$.loadURI(Load.scala:264)
    at sbt.Load$.load(Load.scala:260)
    at sbt.Load$.load(Load.scala:251)
    at sbt.Load$.apply(Load.scala:134)
    at sbt.Load$.defaultLoad(Load.scala:37)
    at sbt.BuiltinCommands$.doLoadProject(Main.scala:473)
    at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:467)
    at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:467)
    at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:60)
    at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:60)
    at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:62)
    at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:62)
    at sbt.Command$.process(Command.scala:95)
    at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:100)
    at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:100)
    at sbt.State$$anon$1.process(State.scala:179)
    at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:100)
    at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:100)
    at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
    at sbt.MainLoop$.next(MainLoop.scala:100)
    at sbt.MainLoop$.run(MainLoop.scala:93)
    at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:71)
    at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:66)
    at sbt.Using.apply(Using.scala:25)
    at sbt.MainLoop$.runWithNewLog(MainLoop.scala:66)
    at sbt.MainLoop$.runAndClearLast(MainLoop.scala:49)
    at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:33)
    at sbt.MainLoop$.runLogged(MainLoop.scala:25)
    at sbt.StandardMain$.runManaged(Main.scala:57)
    at sbt.xMain.run(Main.scala:29)
    at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:109)
    at xsbt.boot.Launch$.withContextLoader(Launch.scala:129)
    at xsbt.boot.Launch$.run(Launch.scala:109)
    at xsbt.boot.Launch$$anonfun$apply$1.apply(Launch.scala:36)
    at xsbt.boot.Launch$.launch(Launch.scala:117)
    at xsbt.boot.Launch$.apply(Launch.scala:19)
    at xsbt.boot.Boot$.runImpl(Boot.scala:44)
    at xsbt.boot.Boot$.main(Boot.scala:20)
    at xsbt.boot.Boot.main(Boot.scala)
[error] sbt.compiler.EvalException: Type error in expression
[error] Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? 

Doing it from outside the app directory I get:

$ sbt about
[info] Loading global plugins from /home/.sbt/0.13/plugins
[info] Set current project to / (in build file:/home/)
[info] This is sbt 0.13.5
[info] The current project is {file:/home/} 0.1-SNAPSHOT
[info] The current project is built against Scala 2.10.4
[info] Available Plugins: sbt.plugins.IvyPlugin, sbt.plugins.JvmPlugin, sbt.plugins.CorePlugin, sbt.plugins.JUnitXmlReportPlugin, EnsimePlugin, com.typesafe.sbt.SbtScalariform
[info] sbt, sbt plugins, and build definitions are using Scala 2.10.4

Answer 1

After the comments, esp. the last one by the OP, I believe the reason may have been a plugin that was installed under ~/.sbt/0.13/plugins that messed up with the latest additions to sbt.Project. That's why I suggested to rename special directories ~/.sbt/0.13 and ~/.sbt/0.13/plugins.

From Global plugins in the official documentation of sbt:

The ~/.sbt/0.13/plugins/ directory is treated as a global plugin definition project. It is a normal sbt project whose classpath is available to all sbt project definitions for that user as described above for per-project plugins.

There was at least one confirmed case where it happened in the past with a plugin that did that - sbt broke with the plugin enabled, and it worked fine without it. See print not accepted in task definition in SBT 0.13?. I think I've seen another, but can't find it now to point here as another reference.