I have some models in my app: [SDPlanBrief.self, SDAirport.self, SDChart.self, SDIndividualRunwayAirport.self, SDLocationBrief.self] SDLocationBrief has a @Relationship with SDChart When I went live with my app I didn't have a versioned schema, but quickly had to change that as I needed to add items to my SDPlanBrief Model. The first versioned schema I made included only the model that I had made a change to. static var models: [any PersistentModel.Type] { [SDPlanBrief.self] } I had made zero changes to my model container and the whole time, and it was working fine. The migration worked well and this is what I was using: .modelContainer(for: [SDAirport.self, SDIndividualRunwayAirport.self, SDLocationBrief.self, SDChart.self, SDPlanBrief.self]) I then saw that to do this all properly, I should actually include ALL of my @Models in the versioned schema: enum AllSwiftDataSchemaV3: VersionedSchema { static var models: [any PersistentModel.Type] { [SDPlanBrief.self, SDAirport.self, SDChart.self, SDIndividualRunwayAirport.self, SDLocationBrief.self] } static var versionIdentifier: Schema.Version = .init(2, 0, 0) } extension AllSwiftDataSchemaV3 { @Model class SDPlanBrief { var destination: String etc... init(destination: String, etc...) { self.destination = destination etc... } } @Model class SDAirport { var catABMinima: String etc... init(catABMinima: String etc...) { self.catABMinima = catABMinima etc... } } @Model class SDChart: Identifiable { var key: String etc... var brief: SDLocationBrief? // @Relationship with SDChart init(key: String etc...) { self.key = key etc... } } @Model class SDIndividualRunwayAirport { var icaoCode: String etc... init(icaoCode: String etc...) { self.icaoCode = icaoCode etc... } } @Model class SDLocationBrief: Identifiable { var briefString: String etc... @Relationship(deleteRule: .cascade, inverse: \SDChart.brief) var chartsArray = [SDChart]() init( briefString: String, etc... chartsArray: [SDChart] = [] ) { self.briefString = briefString etc... self.chartsArray = chartsArray } } } This is ALL my models in here btw. I saw also that modelContainer needed updating to work better for versioned schemas. I changed my modelContainer to look like this: actor ModelContainerActor { @MainActor static func container() -> ModelContainer { let schema = Schema( versionedSchema: AllSwiftDataSchemaV3.self ) let configuration = ModelConfiguration() let container = try! ModelContainer( for: schema, migrationPlan: PlanBriefMigrationPlan.self, configurations: configuration ) return container } } and I am passing in like so: .modelContainer(ModelContainerActor.container()) Each time I run the app now, I suddenly get this message a few times in a row: CoreData: error: Attempting to retrieve an NSManagedObjectModel version checksum while the model is still editable. This may result in an unstable verison checksum. Add model to NSPersistentStoreCoordinator and try again. I typealias all of these models too for the most recent V3 version eg: typealias SDPlanBrief = AllSwiftDataSchemaV3.SDPlanBrief Can someone see if I am doing something wrong here? It seems my TestFlight users are experiencing a crash every now and then when certain views load (I assume when accessing @Query objects). Seems its more so when a view loads quickly, like when removing a subscription view where the data may not have had time to load??? Can someone please have a look and help me out.