Google App Engine - org.datanucleus.exceptions.NucleusUserException: Object Manager has been closed

Question

Why does the code below result in org.datanucleus.exceptions.NucleusUserException: Object Manager has been closed? The exception appears to be thrown at query.getResultList(

Answer 1

the solution that worked for me and a description of the bug i found here:

http://groups.google.com/group/google-appengine-java/browse_thread/thread/945f6ca66c1c587e