objective c - NSPersistentStoreCoordinator has no persistent stores(Schema mismatch or migration failure) core data in ios iOS -

i have added new version of data model. added new fields in new version.also set current model version newly created version.

code update:

 - (nsmanagedobjectmodel *)managedobjectmodel      {          if (_managedobjectmodel != nil) {              return _managedobjectmodel;           }       nsurl *modelurl = [[nsbundle mainbundle] urlforresource:@"ppusfamodel" withextension:@"momd"];         //i earlier ppusfamodel 16, added new model version ppusfamodel 17.        _managedobjectmodel = [[nsmanagedobjectmodel alloc] initwithcontentsofurl:modelurl];             return _managedobjectmodel;         } - (nspersistentstorecoordinator *)persistentstorecoordinator {     if (_persistentstorecoordinator != nil) {         return _persistentstorecoordinator;     }      nsurl *storeurl = [[self applicationdocumentsdirectory] urlbyappendingpathcomponent:sqlitename];      nserror *error = nil;     _persistentstorecoordinator = [[nspersistentstorecoordinator alloc] initwithmanagedobjectmodel:[self managedobjectmodel]];     nsdictionary *options = [nsdictionary dictionarywithobjectsandkeys:                              [nsnumber numberwithbool:yes],   nsmigratepersistentstoresautomaticallyoption,                              [nsnumber numberwithbool:yes],  nsinfermappingmodelautomaticallyoption, nil];      if (![_persistentstorecoordinator addpersistentstorewithtype:nssqlitestoretype configuration:nil url:storeurl options:options error:&error]) {        //error     }      return _persistentstorecoordinator; } 

it worked until attributes added after point getting crash @ following code

- (void)savecontext {      __block nserror *error = nil;     nsmanagedobjectcontext *managedobjectcontext = self.managedobjectcontext;      [managedobjectcontext performblockandwait:^{          if (managedobjectcontext != nil && _persistentstorecoordinator != nil) {              if ([managedobjectcontext haschanges] && ![managedobjectcontext save:&error]) {                 // replace implementation code handle error appropriately.                 // abort() causes application generate crash log , terminate. should not use function in shipping application, although may useful during development.                 // dlog(@"unresolved error %@, %@", error, [error userinfo]);                 //abort();             }         } }]; } 

this crashed screenshot:

when install removing earlier app device works, getting crash when app update on existing version.

//if added field in old model version accidentally instead of new version how fix that?

any appreciated.

the migration failing due model changes. core data can automatically migrate –

• simple addition of new attribute
• removal of attribute
• a non-optional attribute becoming optional
• an optional attribute becoming non-optional , defining default value
• renaming entity or property

to determine if core data can perform automatic migration use nsmappingmodel’s inferredmappingmodelforsourcemodel:destinationmodel:error: method. return nil if core data cannot complete migration.

when core data cannot perform automatic migrations, must use migration manager. apple's documentation provides sample code explain how use migration manager.