Can't find the entity 'id' property for class

[cocodrino]

Hi, I;m receiving an error and it;s not clear for me because I think than my code is pretty similar to the sample provider in the documentation

this is the error

$ sbt run
[info] Loading global plugins from /home/yo/.sbt/0.13/plugins
[info] Set current project to MyProject (in build file:/home/yo/Downloads/proj/scalaPROJ/dbprueba/)
[info] Compiling 1 Scala source to /home/yo/Downloads/proj/scalaPROJ/dbprueba/target/scala-2.10/classes...
[info] Running dbsample.Base 
22:02:28.405 [run-main-0] DEBUG org.reflections.Reflections - going to scan these urls:
    jar:file:/home/yo/.ivy2/cache/net.fwbrasil/activate-core_2.10/jars/activate-core_2.10-1.6.jar!/
    file:/home/yo/Downloads/proj/scalaPROJ/dbprueba/target/scala-2.10/classes/

22:02:28.753 [run-main-0] INFO  org.reflections.Reflections - Reflections took 343 ms to scan 2 urls, producing 43 keys and 813 values 
22:02:28.795 [run-main-0] DEBUG org.reflections.Reflections - going to scan these urls:
    jar:file:/home/yo/.ivy2/cache/net.fwbrasil/activate-core_2.10/jars/activate-core_2.10-1.6.jar!/
    jar:file:/home/yo/.ivy2/cache/net.fwbrasil/activate-prevalent_2.10/jars/activate-prevalent_2.10-1.6.jar!/
    jar:file:/home/yo/.ivy2/cache/net.fwbrasil/activate-prevayler_2.10/jars/activate-prevayler_2.10-1.6.jar!/
    file:/home/yo/Downloads/proj/scalaPROJ/dbprueba/target/scala-2.10/classes/
    jar:file:/home/yo/.ivy2/cache/net.fwbrasil/activate-jdbc_2.10/jars/activate-jdbc_2.10-1.6.jar!/

22:02:29.201 [run-main-0] INFO  org.reflections.Reflections - Reflections took 405 ms to scan 5 urls, producing 153 keys and 3555 values 
[error] (run-main-0) java.lang.ExceptionInInitializerError
java.lang.ExceptionInInitializerError
    at dbsample.Base$delayedInit$body.apply(Base.scala:9)
    at scala.Function0$class.apply$mcV$sp(Function0.scala:40)
    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
    at scala.App$$anonfun$main$1.apply(App.scala:71)
    at scala.App$$anonfun$main$1.apply(App.scala:71)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:32)
    at scala.App$class.main(App.scala:71)
    at dbsample.Base$.main(Base.scala:8)
    at dbsample.Base.main(Base.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
Caused by: java.lang.IllegalStateException: Can't find the entity 'id' property for class dbsample.Person, probably the entity class was loaded before the persistence context. Try to add a 'transactional{}' call on the application startup to force the persistence context load.Please also make sure that there aren't instance variables or methods referencing entities inside the main class.
    at net.fwbrasil.activate.entity.EntityMetadata$$anonfun$11.apply(EntityMetadata.scala:46)
    at net.fwbrasil.activate.entity.EntityMetadata$$anonfun$11.apply(EntityMetadata.scala:46)
    at scala.Option.getOrElse(Option.scala:120)
    at net.fwbrasil.activate.entity.EntityMetadata.<init>(EntityMetadata.scala:45)
    at net.fwbrasil.activate.entity.EntityHelper$$anonfun$initialize$1.apply(EntityHelper.scala:47)
    at net.fwbrasil.activate.entity.EntityHelper$$anonfun$initialize$1.apply(EntityHelper.scala:43)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at net.fwbrasil.activate.entity.EntityHelper$.initialize(EntityHelper.scala:43)
    at net.fwbrasil.activate.entity.id.EntityIdContext$class.$init$(EntityId.scala:109)
    at dbsample.Context$.<init>(Context.scala:9)
    at dbsample.Context$.<clinit>(Context.scala)
    at dbsample.Base$delayedInit$body.apply(Base.scala:9)
    at scala.Function0$class.apply$mcV$sp(Function0.scala:40)
    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
    at scala.App$$anonfun$main$1.apply(App.scala:71)
    at scala.App$$anonfun$main$1.apply(App.scala:71)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:32)
    at scala.App$class.main(App.scala:71)
    at dbsample.Base$.main(Base.scala:8)
    at dbsample.Base.main(Base.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
[trace] Stack trace suppressed: run last compile:run for the full output.
java.lang.RuntimeException: Nonzero exit code: 1
    at scala.sys.package$.error(package.scala:27)
[trace] Stack trace suppressed: run last compile:run for the full output.
[error] (compile:run) Nonzero exit code: 1
[error] Total time: 16 s, completed Jun 27, 2015 10:02:29 PM

my code is really simple..this is the context file

package dbsample

import net.fwbrasil.activate.ActivateContext
import net.fwbrasil.activate.storage.relational.PooledJdbcRelationalStorage
import net.fwbrasil.activate.storage.relational.idiom.h2Dialect



object Context extends ActivateContext {

   val storage = new PooledJdbcRelationalStorage {
      val jdbcDriver = "org.h2.Driver"
      val user = Some("sa")
      val password = Some("")
      val url = "jdbc:h2:mem:my_database;DB_CLOSE_DELAY=-1"
      val dialect = h2Dialect
   }



}

this...the migration

package dbsample


import net.fwbrasil.activate.migration.Migration
import Context._

class CreatePersonTableMigration extends Migration {
   def timestamp = 2012111616051L
   def up = {
      table[Person]
        .createTable(
           _.column[String]("name"))
   }
}

and the last one is the main code

package dbsample

import dbsample.Context._

class Person( var name: String) extends Entity


object Base extends App {
   transactional{}

   transactional {
      new Person("John")
   }

   val john = transactional {
      select[Person].where(_.name :== "John").head
   }

   transactional {
      john.name = "John Doe"
   }

   transactional {
      all[Person].foreach(println)
   }
}

can you notice something bad here?..

thank you so much!!...