The following ScalaTest throws the mentioned exception (strack trace shown below) when it is run:

package eu.swdev.play.form

import org.scalatest.FunSuite

import scala.reflect.runtime.{ universe => ru }

class ReflectionTest extends FunSuite {

  test("reflection test") {

    trait Form {

      private val runtimeMirror = ru.runtimeMirror(this.getClass.getClassLoader)
      private val instanceMirror = runtimeMirror.reflect(this)
      private val members = instanceMirror.symbol.typeSignature.members

    }

    val f1 = new Form {
      val a = 1
    }

    val f2 = new Form {
      val b = f1.a
    }

  }

}

no-symbol does not have an owner
scala.reflect.internal.FatalError: no-symbol does not have an owner
at scala.reflect.internal.SymbolTable.abort(SymbolTable.scala:49)
at scala.reflect.internal.Symbols$NoSymbol.owner(Symbols.scala:3248)
at scala.reflect.internal.Symbols$Symbol.newSyntheticValueParam(Symbols.scala:346)
at scala.reflect.internal.Symbols$Symbol$$anonfun$newSyntheticValueParams$1.apply(Symbols.scala:340)
at scala.reflect.internal.Symbols$Symbol$$anonfun$newSyntheticValueParams$1.apply(Symbols.scala:340)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.immutable.List.foreach(List.scala:318)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
at scala.collection.AbstractTraversable.map(Traversable.scala:105)
at scala.reflect.internal.Symbols$Symbol.newSyntheticValueParams(Symbols.scala:340)
at scala.reflect.internal.Symbols$Symbol.newSyntheticValueParams(Symbols.scala:337)
at scala.reflect.runtime.JavaMirrors$JavaMirror.setMethType(JavaMirrors.scala:1093)
at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$JavaMirror$$jmethodAsScala1(JavaMirrors.scala:1112)
at scala.reflect.runtime.JavaMirrors$JavaMirror$$anonfun$scala$reflect$runtime$JavaMirrors$JavaMirror$$jmethodAsScala$1.apply(JavaMirrors.scala:1103)
at scala.reflect.runtime.JavaMirrors$JavaMirror$$anonfun$scala$reflect$runtime$JavaMirrors$JavaMirror$$jmethodAsScala$1.apply(JavaMirrors.scala:1103)
at scala.reflect.runtime.JavaMirrors$JavaMirror$$anonfun$toScala$1.apply(JavaMirrors.scala:104)
at scala.reflect.runtime.TwoWayCache.toScala(TwoWayCache.scala:38)
at scala.reflect.runtime.JavaMirrors$JavaMirror.toScala(JavaMirrors.scala:102)
at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$JavaMirror$$jmethodAsScala(JavaMirrors.scala:1103)
at scala.reflect.runtime.JavaMirrors$JavaMirror$FromJavaClassCompleter$$anonfun$1$$anonfun$apply$mcV$sp$2.apply(JavaMirrors.scala:707)
at scala.reflect.runtime.JavaMirrors$JavaMirror$FromJavaClassCompleter$$anonfun$1$$anonfun$apply$mcV$sp$2.apply(JavaMirrors.scala:706)
at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:108)
at scala.reflect.runtime.JavaMirrors$JavaMirror$FromJavaClassCompleter$$anonfun$1.apply$mcV$sp(JavaMirrors.scala:706)
at scala.reflect.runtime.JavaMirrors$JavaMirror$FromJavaClassCompleter.completeRest(JavaMirrors.scala:720)
at scala.reflect.runtime.JavaMirrors$JavaMirror$FromJavaClassCompleter.complete(JavaMirrors.scala:667)
at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1229)
at scala.reflect.internal.Symbols$Symbol.initialize(Symbols.scala:1365)
at scala.reflect.internal.Definitions$DefinitionsClass.fullyInitializeSymbol(Definitions.scala:226)
at scala.reflect.internal.Symbols$SymbolContextApiImpl.typeSignature(Symbols.scala:98)
at scala.reflect.internal.Symbols$SymbolContextApiImpl.typeSignature(Symbols.scala:73)
at eu.swdev.play.form.ReflectionTest$$anonfun$1$Form$1$class.$init$(ReflectionTest.scala:17)
at eu.swdev.play.form.ReflectionTest$$anonfun$1$$anon$2.(ReflectionTest.scala:25)
at eu.swdev.play.form.ReflectionTest$$anonfun$1.apply$mcV$sp(ReflectionTest.scala:25)
at eu.swdev.play.form.ReflectionTest$$anonfun$1.apply(ReflectionTest.scala:11)
at eu.swdev.play.form.ReflectionTest$$anonfun$1.apply(ReflectionTest.scala:11)