Well, I've finally managed to resolve my problem: The org/datanucleus/enhancer/DataNucleusEnhancer.class was found in eclipse/plugins/com.google.appengine.eclipse.sdkbundle_1.6.1.v201201120043r37/new_appengine-java-sdk-1.6.1/lib/opt/tools/datanucleus/v2
but I was including new_appengine-java-sdk-1.6.1/lib/opt/user/datanucleus/v2 instead of new_appengine-java-sdk-1.6.1/lib/opt/tools/datanucleus/v2 in my Window -> Preferences -> DataNucleus settings. Duh, I really feel like a fool but I'm glad that in the end I was able to follow through the instructions and get there. Regards, JG -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.