I've just tried to create a lot of nodes and the content service seems to quietly fail. If I hit the node via id in the backoffice I can see an unpublished copy. Attempting to publish gives: Server error: Contact administrator, see log for full details. Cannot save a non-current version. I think it might be something to do with having switched / added languages to Umbraco at some point. Has anyone seen similar - how do I recover this?