Using @ElementCollection annotation causes false positive validation errors, such as "entity name is empty", "class not marked as embeddable" etc. Seems similar to this old bug: https://issues.jboss.org/browse/JBIDE-16016 I'm attaching a simple Eclipse project that reproduces the errors. Same behaviour occurs on both Jboss Dev Studio 8.0.0.GA and Eclipse Luna with Hibernate Tools 4.0.0 installed. Posted by forums Original post: https://developer.jboss.org/message/919915#919915