Исключение RESTKit: не было найдено отображаемых представлений объектов по ключевым путям, в которых выполнялся поиск.

У меня проблема. Сервер получил запрос, но отображение не обрабатывается правильно. Я не понимаю, что делаю не так.

Бревно:

    2016-04-25 19:39:16.114 cifrosvit[1063:15363] I restkit:RKLog.m:49 RestKit logging initialized...
2016-04-25 19:39:16.413 cifrosvit[1063:15363] I restkit.network:RKObjectRequestOperation.m:150 GET 'http://cifrosvit.com/api/get_info/?info=banners'
2016-04-25 19:39:17.188 cifrosvit[1063:15505] I restkit.network:RKObjectRequestOperation.m:222 GET 'http://cifrosvit.com/api/get_info/?info=banners' (200 OK / 7 objects) [request=0.7722s mapping=0.0021s total=0.8101s]
2016-04-25 19:41:17.508 cifrosvit[1063:15363] I restkit.network:RKObjectRequestOperation.m:150 GET 'http://cifrosvit.com/api/user.sign_up/?adr=terwtrwe&city=fwferwtw&email=yrurweqrqw%40rfewq.rewq&name=fsdfsdfdsa&password=12345&phone_mob=54323425342'
2016-04-25 19:41:18.040 cifrosvit[1063:16373] D restkit.object_mapping:RKMapperOperation.m:407 Executing mapping operation for representation: {
    data =     (
    );
    errors =     (
    );
    success = true;
}
 and targetObject: (null)
2016-04-25 19:41:18.040 cifrosvit[1063:16373] D restkit.object_mapping:RKMapperOperation.m:433 Finished performing object mapping. Results: (null)
2016-04-25 19:41:18.041 cifrosvit[1063:16374] E restkit.network:RKObjectRequestOperation.m:215 GET 'http://cifrosvit.com/api/user.sign_up/?adr=terwtrwe&city=fwferwtw&email=yrurweqrqw%40rfewq.rewq&name=fsdfsdfdsa&password=12345&phone_mob=54323425342' (200 OK / 0 objects) [request=0.5320s mapping=0.0000s total=0.5345s]: Error Domain=org.restkit.RestKit.ErrorDomain Code=1001 "No response descriptors match the response loaded." UserInfo={NSLocalizedFailureReason=A 200 response was loaded from the URL 'http://cifrosvit.com/api/user.sign_up/?adr=terwtrwe&city=fwferwtw&email=yrurweqrqw%40rfewq.rewq&name=fsdfsdfdsa&password=12345&phone_mob=54323425342', which failed to match all (0) response descriptors:, NSErrorFailingURLStringKey=http://cifrosvit.com/api/user.sign_up/?adr=terwtrwe&city=fwferwtw&email=yrurweqrqw%40rfewq.rewq&name=fsdfsdfdsa&password=12345&phone_mob=54323425342, NSErrorFailingURLKey=http://cifrosvit.com/api/user.sign_up/?adr=terwtrwe&city=fwferwtw&email=yrurweqrqw%40rfewq.rewq&name=fsdfsdfdsa&password=12345&phone_mob=54323425342, NSUnderlyingError=0x7fa58a300000 {Error Domain=org.restkit.RestKit.ErrorDomain Code=1001 "No mappable object representations were found at the key paths searched." UserInfo={NSLocalizedDescription=No mappable object representations were found at the key paths searched., NSLocalizedFailureReason=The mapping operation was unable to find any nested object representations at the key paths searched: 
The representation inputted to the mapper was found to contain nested object representations at the following key paths: data, errors, success
This likely indicates that you have misconfigured the key paths for your mappings., keyPath=null, DetailedErrors=(
)}}, keyPath=null, NSLocalizedDescription=No response descriptors match the response loaded.}

Код:

RKObjectMapping* objectMapping = [RKObjectMapping mappingForClass:[ResponseModel class]];
    [objectMapping addAttributeMappingsFromArray:@[@"success", @"errors"]];
    [objectMapping addPropertyMapping:[RKRelationshipMapping
                                       relationshipMappingFromKeyPath:@"data"
                                                            toKeyPath:@"data"
                                                          withMapping:[RKObjectMapping mappingForClass:[NSArray class]]]
     ];
    RKResponseDescriptor* responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:objectMapping
                                                                           method:RKRequestMethodPOST
                                                                      pathPattern:@"user.sign_up/"
                                                                          keyPath:nil
                                                                      statusCodes:[NSIndexSet indexSetWithIndex:200]];
AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:@"http://cifrosvit.com/api/"]];
    RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];
    [objectManager addResponseDescriptor:responseDescriptor];
    RKLogConfigureByName("RestKit/ObjectMapping", RKLogLevelTrace);

    [objectManager getObjectsAtPath:responseDescriptor.pathPattern parameters:params success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
        NSLog(@"success");
    } failure:^(RKObjectRequestOperation *operation, NSError *error) {
        NSLog(@"failure");
    }];

ResponseModel интерфейс:

@interface ResponseModel : NSObject

@property NSString* success;
@property id data;
@property (strong, nonatomic) NSArray* errors;

@end

Запрос:

{
  "success": "true",
  "data": [],
  "errors": []
}

Почему RESTKIT всегда вызывает блокировку сбоя?