Hi, I am having troubles with Voyage and Mongo. I have some Classes that I save in Mongo, say "One", "Two", and "Three". All three classes and are voyage roots, so the objects from each class are stored in different collections. One objects has a reference to Two or Three objects. The problem arises when I use a Magritte description and define a Mongo container to optimize the storage: since each class is stored in its own collection, there is no point in storing the #instanceOf attribute as well. Two>>mongoContainer <mongoContainer> ^ VOMongoContainer new kind: Two; yourself If I add this method, when I try to load an object One, I get the exception: "KeyNotFound: key #nil not found in SystemDictionary". It looks like Voyage is not able to understand the type of the objects stored in the collection Two, when loaded from a reference. Am I missing something? Do I need to specify something more to make it work? I reproduced the scenario in an image that can be downloaded here: https://dl.dropboxusercontent.com/u/11506662/VoyageMongo-Link-Test.zip Do you have any idea? Should I report this on the issue tracker? Thanks! Tommaso