This question has already been asked, but has received [no answers](https://stackoverflow.com/questions/27791594/watchkit-core-data-sync-up).

My iOS app and my WatchKit extension share an App Group in which a Core Data store persists. The Core Data model (simplified) is a Person object that has an attribute for Age. Both the app and extension can change the age at will.

If the value for a person changes on the watch, the app does not reflect it unless I close and rerun the app. Same going the opposite direction.

If I try to change the age on the watch to 20, and change the age on the phone to 30, then I get an error having to do with merge conflicts, because I am not using the most up-to-date version of the NSManagedObject on one of the devices (whichever I change the age on last).

How can I make the two work together without any issues?