I have a problem with subqueries and abstract classes. I am using fluent nhibernate and we have a testcase that assures all mappings are ok (http://ayende.com/Blog/archive/2006/08/ ... hecks.aspx). Everything works well except now that I wanted to create a subquery for a certain abstract class. When I run the query and subquery I receive a message that says "no persister for: <abstract classname>". This abstract class can be used without problems in standard queries but not in subqueries. I can also use normal classes in subqueries. I have also seen other people having problems with subqueries that use a interface which is quite similar to a abstract class. Nobody has received an answer to their questions though and I wonder if anyone on this forum have had the same problem? Is it a bug in nhibernate or is it a feature?