The following schema runs fine (using hibernate-entitymanager 4.0.1.Final):

@Entity // I left off the getters, setters, etc.
class MyEntity{
@ElementCollection
Collection<MyEmbeddable> myEmbeddables;
}
@Embeddable
class MyEmbeddable{
Integer value;
}

But when I nest an embeddable within MyEmbeddable, I run into trouble.

@Entity
class MyEntity{
@ElementCollection
Collection<MyEmbeddable> myEmbeddables;
}
@Embeddable
class MyEmbeddable{
MyNestedEmbeddable myNestedEmbeddable;
}
@Embeddable
class MyNestedEmbeddable{
Integer value;
}

Before Hibernate creates any database tables, I get the following error:

Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
at org.hibernate.persister.collection.AbstractCollectionPersister.initCollectionPropertyMap(AbstractCollectionPersister.java:1727)
at org.hibernate.persister.collection.AbstractCollectionPersister.initCollectionPropertyMap(AbstractCollectionPersister.java:1706)
at org.hibernate.persister.collection.AbstractCollectionPersister.<init>(AbstractCollectionPersister.java:602)
at org.hibernate.persister.collection.BasicCollectionPersister.<init>(BasicCollectionPersister.java:73)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:226)
... 50 more

Thanks in advance for any help.