Hi, I would like to make a proposition to extend the 'EnsureArgumentNotNull' exception in the following case:

at Xtensive.Core.ArgumentValidator.EnsureArgumentNotNull(Object value, String parameterName) at Xtensive.Storage.EntityEventBroker.AddSubscriber(Key key, FieldInfo fieldInfo, Object eventKey, Delegate subscriber) at Xtensive.Storage.EntityEventBroker.RemapKeys(KeyMapping keyMapping) at Xtensive.Storage.Session.RemapEntityKeys(KeyMapping keyMapping) at Xtensive.Storage.DisconnectedState.ApplyChanges(Session targetSession) at Xtensive.Storage.DisconnectedState.ApplyChanges()

I had created some entities and tried to save them. I made an error and left a navigation property 'null' that is not nullable. Now I get the exception "Value cannot be null.\r\nParameter name: subscriber" which is perfectly ok. But I am missing the info which one of the entities produces the problem. May I propose to add the Key of the entity to the 'Data' collection? In our system we are dumping the Data collection always if we get an exception. This would help.

Thanks

This thread was imported from our support forum. The original discussion may contain more detailed answer. Original topic by AndresRohr.