Failed to save to data store: The operation couldn’t be completed. (Cocoa error 133020.)

Question

I am working on quite complex app with huge sync procedure beetwen iphone and web server. I have no troubles with adding records, until I run sync procedure in separete thread, and It will update data on serwer, and send them back to iphone. But after this procedure, inserting new data cause error, such as this:

2011-01-07 12:49:10.722 App[1987:207] Failed to save to data store: The operation couldn’t be completed. (Cocoa error 133020.)
2011-01-07 12:49:10.724 App[1987:207]   {
    conflictList =     (
        "NSMergeConflict (0x5ac1ea0) for NSManagedObject (0x5a2d710) with objectID '0x5a27080 <x-coredata://E82E75ED-96DB-4CBF-9D15-9CC106AC0052/uzytkownicy/p10>' with oldVersion = 9 and newVersion = 21 and old object snapshot = {\n    adres = \"<null>\";\n    haslo = xxxxxxxxxxxxxxxxxxxxxx;\n    \"id_uzytkownika\" = 3;\n    imie = Jan;\n    \"kod_jednorazowy\" = 0;\n    komorka = \"<null>\";\n    login = nowakjan;\n    nazwisko = Nowak;\n    pesel = 0;\n    rodzaj = 2;\n    \"stan_konta\" = 0;\n    telefon = \"<null>\";\n    \"uzytkownicy_uczniowie\" = \"<null>\";\n    \"zmienna_losowa\" = 8G9e1;\n} and new cached row = {\n    adres = \"<null>\";\n    haslo = xxxxxxxxxxxxxxxxxxxxxx;\n    \"id_uzytkownika\" = 3;\n    imie = Jan;\n    \"kod_jednorazowy\" = 0;\n    komorka = \"<null>\";\n    login = nowakjan;\n    nazwisko = Nowak;\n    pesel = 0;\n    rodzaj = 2;\n    \"stan_konta\" = 0;\n    telefon = \"<null>\";\n    \"uzytkownicy_uczniowie\" = \"<null>\";\n    \"zmienna_losowa\" = 8G9e1;\n}",
        "NSMergeConflict (0xd266990) for NSManagedObject (0xcd05950) with objectID '0x5a453b0 <x-coredata://E82E75ED-96DB-4CBF-9D15-9CC106AC0052/uczniowie/p125>' with oldVersion = 5 and newVersion = 10 and old object snapshot = {\n    adres = \"Warszawa; ul. Lwowska 32\";\n    \"data_urodzenia\" = \"1997-02-01 23:00:00 +0000\";\n    dysfunkcje = \"\";\n    email = \"<null>\";\n    frekwencja = 0;\n    \"id_ucznia\" = 86;\n    imie2 = Marian;\n    \"imie_ucznia\" = \"S\\U0142awomir\";\n    klasa = \"0x5a47820 <x-coredata://E82E75ED-96DB-4CBF-9D15-9CC106AC0052/zespoly/p9>\";\n    komorka = \"<null>\";\n    \"miejsce_urodzenia\" = Warszawa;\n    \"nazwisko_ucznia\" = \"S\\U0142awek\";\n    \"numer_ewidencyjny\" = 20;\n    opiekun1 = \"Mariusz S\\U0142awek\";\n    opiekun2 = \" \";\n    pesel = 97020298919;\n    plec = 1;\n    telefon = 890000002;\n    \"uzytkownicy_uczniowie\" = \"<null>\";\n    \"web_klasa\" = 50;\n} and new cached row = {\n    adres = \"Warszawa; ul. Lwowska 32\";\n    \"data_urodzenia\" = \"1997-02-01 23:00:00 +0000\";\n    dysfunkcje = \"\";\n    email = \"<null>\";\n    frekwencja = 0;\n    \"id_ucznia\" = 86;\n    imie2 = Marian;\n    \"imie_ucznia\" = \"S\\U0142awomir\";\n    klasa = \"0x5a8e7c0 <x-coredata://E82E75ED-96DB-4CBF-9D15-9CC106AC0052/zespoly/p9>\";\n    komorka = \"<null>\";\n    \"miejsce_urodzenia\" = Warszawa;\n    \"nazwisko_ucznia\" = \"S\\U0142awek\";\n    \"numer_ewidencyjny\" = 20;\n    opiekun1 = \"Mariusz S\\U0142awek\";\n    opiekun2 = \" \";\n    pesel = 97020298919;\n    plec = 1;\n    telefon = 890000002;\n    \"uzytkownicy_uczniowie\" = \"<null>\";\n    \"web_klasa\" = 50;\n}",
        "NSMergeConflict (0xd2669b0) for NSManagedObject (0x5a44480) with objectID '0x5a47830 <x-coredata://E82E75ED-96DB-4CBF-9D15-9CC106AC0052/przedmioty/p12>' with oldVersion = 7 and newVersion = 15 and old object snapshot = {\n    \"id_przedmiotu\" = 1;\n    \"nazwa_przedmiotu\" = Historia;\n    \"skrot_nazwy\" = Hist;\n} and new cached row = {\n    \"id_przedmiotu\" = 1;\n    \"nazwa_przedmiotu\" = Historia;\n    \"skrot_nazwy\" = Hist;\n}"
    );
}

I've been looking for any solution but without luck.

Thank You in advance for any usefull help.

---

    oceny_ucznia *nowaOcenka = (oceny_ucznia *)[NSEntityDescription insertNewObjectForEntityForName:@"oceny_ucznia" inManagedObjectContext:[Factory getVar:@"context"]];

    nowaOcenka.przedmiot                = (przedmioty *) [Factory getVar:@"cPrzedmiot"];
    nowaOcenka.web_przedmiot            = [NSNumber numberWithInt:[((przedmioty *)[Factory getVar:@"cPrzedmiot"]).id_przedmiotu intValue]];
    nowaOcenka.nauczyciel               = (uzytkownicy *)[Factory getVar:@"cNauczyciel"];
    nowaOcenka.web_nauczyciel           = [NSNumber numberWithInt:[((uzytkownicy *)[Factory getVar:@"cNauczyciel"]).id_uzytkownika intValue]];
    nowaOcenka.lekcja                   = (lekcje *)[Factory getVar:@"cLekcja"];
    nowaOcenka.uczen                    = uczeniek;
    nowaOcenka.web_uczen                = [NSNumber numberWithInt:[uczeniek.id_ucznia intValue]];
    nowaOcenka.czas_wpisania            = [NSDate date];

    if ( grupka != nil ) {
        nowaOcenka.grupa                = grupka;
        nowaOcenka.web_grupa            = [NSNumber numberWithInt:[grupka.id_grupy_ocen intValue]];
        nowaOcenka.kolumna              = [NSNumber numberWithInt:([kolumienka intValue]+1)];
        nowaOcenka.grupa.czas_wpisania  = [NSDate date];
    } else {
        int wartoscOceny                = [[Factory getVar:@"cSemestr"] intValue];
        wartoscOceny                   += ( [kolumienka intValue]==0 ) ? 2 : 0;
        nowaOcenka.koncowa              = [NSNumber numberWithInt:wartoscOceny];
    }

    nowaOcenka.wartosc                  = [NSNumber numberWithFloat:[[((slownik_ocen *)[self.slownikOcen objectAtIndex:[ocena selectedRowInComponent:0]]) wartosc_liczbowa] floatValue]];
    nowaOcenka.ocena                    = [NSString stringWithFormat:@"%@",[((slownik_ocen *)[self.slownikOcen objectAtIndex:[ocena selectedRowInComponent:0]]) ocena_opis]];
    nowaOcenka.semestr                  = [NSNumber numberWithInt:[[Factory getVar:@"cSemestr"] intValue]];

    ((lekcje *)[Factory getVar:@"cLekcja"]).czas_wpisania = [NSDate date];

    NSError* error;
if(![[Factory getVar:@"context"] save:&error]) {
        NSLog(@"Failed to save to data store: %@", [error localizedDescription]);
        NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey];
        if(detailedErrors != nil && [detailedErrors count] > 0) {
            for(NSError* detailedError in detailedErrors) {
                NSLog(@"  DetailedError: %@", [detailedError userInfo]);
            }
        }
        else {
            NSLog(@"  %@", [error userInfo]);
        }
}

Factory class is described here, but probablly there is a problem with a context that is not refreshed accurately after sync procedure.

Answer 1

According to:

http://developer.apple.com/library/ios/#documentation/cocoa/Reference/CoreDataFramework/Miscellaneous/CoreData_Constants/Reference/reference.html

that error is NSManagedObjectMergeError:

Error code to denote that a merge policy failed—Core Data is unable to complete merging.

The NSError object may be able to help in decoding this error. Can you post the code you are using to insert the new data?