OK, this is deeper problem, than I anticipated earlier. There is a problem of interfaces/abstract classes, if you explicitly use interface/abstract class Type(Info) as a parameter in MetaTypeFactory.create. Since that is what is then used to create metatype instance, from which we later on gather information to do the unwrapping (for composite and collection). Thus failing to instantiate new instance. But if you use straight MetaTypeFactory.create with only value parameter, it should go through. Adrian, what's to do here? Using the more restrictive TypeInfo in DefaultMetaValueFactory.internalCreate? | protected MetaValue internalCreate(Object value, TypeInfo type, MetaType metaType) | { | if (value == null) | return null; | | if (type == null || (type instanceof ClassInfo && ((ClassInfo)type).isInterface())) | type = configuration.getTypeInfo(value.getClass()); | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4112006#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...