I want to do migration with 2 core database. I have read apple developer document. For the first database, I add some attributes (string, integer and date properties) to new version database. And follow all steps, I have done migration successfully with the first once. But the second database, I also add attributes (string, integer, date, transformable and binary-data properties) to new version database. And follow all steps (like the first database) but system return an error (134130). Here is the code: if (persistentStoreCoordinator_) { PMReleaseSafely(persistentStoreCoordinator_); } // Notify NSNotificationCenter *nc = [NSNotificationCenter defaultCenter]; [nc postNotificationName:GCalWillMigrationNotification object:self]; // NSString *sourceStoreType = NSSQLiteStoreType; NSString *dataStorePath = [PMUtility dataStorePathForName:GCalDBWarehousePersistentStoreName]; NSURL *storeURL = [NSURL fileURLWithPath:dataStorePath]; BOOL storeExists = [[NSFileManager defaultManager] fileExistsAtPath:dataStorePath]; // NSError *error = nil; NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil]; persistentStoreCoordinator_ = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:self.managedObjectModel]; [persistentStoreCoordinator_ addPersistentStoreWithType:sourceStoreType configuration:nil URL:storeURL options:options error:&error]; if (error != nil) { abort(); } error is not nil and below is log: Error Domain=NSCocoaErrorDomain Code=134130 "The operation couldn\u2019t be completed. (Cocoa error 134130.)" UserInfo=0x856f790 {URL=file://localhost/Users/greensun/Library/Application%20Support/iPhone%20Simulator/5.0/Applications/D10712DE-D9FE-411A-8182-C4F58C60EC6D/Library/Application%20Support/Promise%20Mail/GCalDBWarehouse.sqlite, metadata={type = immutable dict, count = 7, entries = 2 : {contents = "NSStoreModelVersionIdentifiers"} = {type = immutable, count = 1, values = ( 0 : {contents = ""} )} 4 : {contents = "NSPersistenceFrameworkVersion"} = {value = +386, type = kCFNumberSInt64Type} 6 : {contents = "NSStoreModelVersionHashes"} = {type = immutable dict, count = 2, entries = 0 : {contents = "SyncEvent"} = {length = 32, capacity = 32, bytes = 0xfdae355f55c13fbd0344415fea26c8bb ... 4c1721aadd4122aa} 1 : {contents = "ImportEvent"} = {length = 32, capacity = 32, bytes = 0x7676888f0d7eaff4d1f844343028ce02 ... 040af6cbe8c5fd01} } 7 : {contents = "NSStoreUUID"} = {contents = "51678BAC-CCFB-4D00-AF5C-8FA1BEDA6440"} 8 : {contents = "NSStoreType"} = {contents = "SQLite"} 9 : {contents = "_NSAutoVacuumLevel"} = {contents = "2"} 10 : {contents = "NSStoreModelVersionHashesVersion"} = {value = +3, type = kCFNumberSInt32Type} }, reason=Can't find model for source store} I try a lot of solutions but it does not work. I just add more attributes to 2 new version database, and succeed in migrating once. Thanks for reading and your help.