I am maintaining an app that has been live on the AppStore for a few months. My app uses Core Data and somehow I managed to lose all previous versions of my xcdatamodel.
I am hoping to perform a lightweight migration. All I need to do is add one attribute to one of my entities. So, I have followed the correct steps of creating a model version.
Apparently, I modified the original xcdatamodel. So, when I test the migration, it fails with an error Code=134130 "Can't find model for source store". Since the app runs fine when there is no sqlite file on the device/simulator, I've concluded that the original xcdatamodel has been modified.
Assuming my logic thus far holds, how can I create an xcdatamodel that will match the sqlite files on my users' devices. It's not acceptable for them to lose their data.
Thank you.
With a Core Data model file open (eg a blank one), choose Editor -> Import, and then find the .mom file from the previous version of your app.
See this answer.