When I try to delete an answer that has a related question that is hidden, I get the folloing message:
Question2Answer query failed:
DELETE FROM qa_posts WHERE postid=...
Error 1451: Cannot delete or update a parent row: a foreign key constraint fails (`qa/qa_posts`, CONSTRAINT `qa_posts_ibfk_2` FOREIGN KEY (`parentid`) REFERENCES `qa_posts` (`postid`))
I understand why the error occurs, but I think in this situation the delete link should not be shown (or, at least, the error message should provide some useful information).