Using SBT and Scala Plugin with company proxy repository does not work

I just upgraded to IDEA 14.1.2, and now I am trying to create an SBT project. I set our private proxy in ~/.sbt/repositories, and using sbt on the console works with it. But when I try to import it, I get:

java.lang.UnsupportedOperationException: Position.start on class scala.reflect.internal.util.OffsetPosition
        at scala.reflect.internal.util.Position.start(Position.scala:114)
        at sbt.internals.parser.SbtParser.sbt$internals$parser$SbtParser$$convertStatement$1(SbtParser.scala:148)
        at sbt.internals.parser.SbtParser$$anonfun$4.apply(SbtParser.scala:153)
        at sbt.internals.parser.SbtParser$$anonfun$4.apply(SbtParser.scala:153)
        at scala.collection.TraversableLike$$anonfun$flatMap$1.apply(TraversableLike.scala:251)
        at scala.collection.TraversableLike$$anonfun$flatMap$1.apply(TraversableLike.scala:251)
        at scala.collection.immutable.List.foreach(List.scala:318)
        at scala.collection.TraversableLike$class.flatMap(TraversableLike.scala:251)
        at scala.collection.AbstractTraversable.flatMap(Traversable.scala:105)
        at sbt.internals.parser.SbtParser.splitExpressions(SbtParser.scala:153)
        at sbt.internals.parser.SbtParser.<init>(SbtParser.scala:58)
        at sbt.EvaluateConfigurations$.splitExpressions(EvaluateConfigurations.scala:226)
        at sbt.EvaluateConfigurations$.parseConfiguration(EvaluateConfigurations.scala:69)
        at sbt.EvaluateConfigurations$.evaluateSbtFile(EvaluateConfigurations.scala:106)
        at sbt.Load$.sbt$Load$$loadSettingsFile$1(Load.scala:712)
        at sbt.Load$$anonfun$sbt$Load$$memoLoadSettingsFile$1$1.apply(Load.scala:717)
        at sbt.Load$$anonfun$sbt$Load$$memoLoadSettingsFile$1$1.apply(Load.scala:716)
        at scala.collection.MapLike$class.getOrElse(MapLike.scala:128)
        at scala.collection.AbstractMap.getOrElse(Map.scala:58)
        at sbt.Load$.sbt$Load$$memoLoadSettingsFile$1(Load.scala:716)
        at sbt.Load$$anonfun$loadFiles$1$2.apply(Load.scala:723)
        at sbt.Load$$anonfun$loadFiles$1$2.apply(Load.scala:723)
        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
        at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
        at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
        at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
        at scala.collection.AbstractTraversable.map(Traversable.scala:105)
        at sbt.Load$.loadFiles$1(Load.scala:723)
        at sbt.Load$.discoverProjects(Load.scala:734)
        at sbt.Load$.discover$1(Load.scala:545)
        at sbt.Load$.loadTransitive(Load.scala:574)
        at sbt.Load$.loadProjects$1(Load.scala:442)
        at sbt.Load$.loadUnit(Load.scala:446)
        at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:281)
        at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:281)
        at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:91)
        at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:90)
        at sbt.BuildLoader.apply(BuildLoader.scala:140)
        at sbt.Load$.loadAll(Load.scala:334)
        at sbt.Load$.loadURI(Load.scala:289)
        at sbt.Load$.load(Load.scala:285)
        at sbt.Load$.load(Load.scala:276)
        at sbt.Load$.apply(Load.scala:130)
        at sbt.Load$.buildPluginDefinition(Load.scala:821)
        at sbt.Load$.buildPlugins(Load.scala:787)
        at sbt.Load$.plugins(Load.scala:775)
        at sbt.Load$.loadUnit(Load.scala:431)
        at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:281)
        at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:281)
        at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:91)
        at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:90)
        at sbt.BuildLoader.apply(BuildLoader.scala:140)
        at sbt.Load$.loadAll(Load.scala:334)
        at sbt.Load$.loadURI(Load.scala:289)
        at sbt.Load$.load(Load.scala:285)
        at sbt.Load$.load(Load.scala:276)
        at sbt.Load$.apply(Load.scala:130)
        at sbt.Load$.defaultLoad(Load.scala:36)
        at sbt.BuiltinCommands$.doLoadProject(Main.scala:481)
        at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:475)
        at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:475)
        at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:58)
        at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:58)
        at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:60)
        at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:60)
        at sbt.Command$.process(Command.scala:92)
        at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:98)
        at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:98)
        at sbt.State$$anon$1.process(State.scala:184)
        at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:98)
        at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:98)
        at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
        at sbt.MainLoop$.next(MainLoop.scala:98)
        at sbt.MainLoop$.run(MainLoop.scala:91)
        at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:70)
        at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:65)
        at sbt.Using.apply(Using.scala:24)
        at sbt.MainLoop$.runWithNewLog(MainLoop.scala:65)
        at sbt.MainLoop$.runAndClearLast(MainLoop.scala:48)
        at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:32)
        at sbt.MainLoop$.runLogged(MainLoop.scala:24)
        at sbt.StandardMain$.runManaged(Main.scala:53)
        at sbt.xMain.run(Main.scala:28)
        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] java.lang.UnsupportedOperationException: Position.start on class scala.reflect.internal.util.OffsetPosition
[error] Use 'last' for the full log.

My build.sbt is the simplest I can possibly create:

name := "simple"
version := "1.0"
scalaVersion := "2.11.6"

What am I missing? Or did I find a bug?

EDIT: This also happens when I create a new blank SBT project with IDEA.