Parse iOS XCode: Class names cannot start with an underscore

Question

I am getting this error at initialization of Parse. Most likely it is because I updated to XCode Version 16.0 (16A242d). MacOS is 14.5 (23F79).

I have installed Parse as a pod. Also tried to remove it and install latest version as a Package Dependency but same error.

[Parse initializeWithConfiguration:[ParseClientConfiguration configurationWithBlock:^(id<ParseMutableClientConfiguration> configuration) {
            configuration.applicationId = @"myAppId";
            configuration.clientKey = nil;
            configuration.server = @"myParseServerUrlStringHostedonHeroku";
}]];

Here is what I get when I run the app: (No errors while compiling.)

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: Invalid class name. Class names cannot start with an underscore.'
*** First throw call stack:
(
    0   CoreFoundation                      0x00000001804ae0f8 __exceptionPreprocess + 172
    1   libobjc.A.dylib                     0x0000000180087db4 objc_exception_throw + 56
    2   CoreFoundation                      0x00000001804ae008 -[NSException initWithCoder:] + 0
    3   myApp.debug.dylib   0x0000000106d2f1f8 +[PFObject(Private) _assertValidInstanceClassName:] + 180
    4   myApp.debug.dylib   0x0000000106d37598 -[PFObject init] + 436
    5   myApp.debug.dylib   0x0000000106d37898 -[PFObject initWithObjectState:] + 92
    6   myApp.debug.dylib   0x0000000106d379cc +[PFObject objectWithClassName:objectId:completeData:] + 248
    7   myApp.debug.dylib   0x0000000106d37ae0 +[PFObject objectWithClassName:] + 80
    8   myApp.debug.dylib   0x0000000106d37fcc +[PFObject object] + 252
    9   myApp.debug.dylib   0x0000000106cf6bdc __56-[PFCurrentInstallationController getCurrentObjectAsync]_block_invoke.9 + 452
    10  myApp.debug.dylib   0x0000000106a64f18 __62-[BFTask continueWithExecutor:successBlock:cancellationToken:]_block_invoke + 124
    11  myApp.debug.dylib   0x0000000106a64848 __55-[BFTask continueWithExecutor:block:cancellationToken:]_block_invoke + 88
    12  myApp.debug.dylib   0x0000000106a615c0 __29+[BFExecutor defaultExecutor]_block_invoke_2 + 152
    13  myApp.debug.dylib   0x0000000106a61da0 -[BFExecutor execute:] + 88
    14  myApp.debug.dylib   0x0000000106a64b24 __55-[BFTask continueWithExecutor:block:cancellationToken:]_block_invoke.15 + 44
    15  myApp.debug.dylib   0x0000000106a642f4 -[BFTask runContinuations] + 508
    16  myApp.debug.dylib   0x0000000106a63cd8 -[BFTask trySetResult:] + 208
    17  myApp.debug.dylib   0x0000000106a65a50 -[BFTaskCompletionSource trySetResult:] + 88
    18  myApp.debug.dylib   0x0000000106ce88fc __28-[PFAsyncTaskQueue enqueue:]_block_invoke_2 + 216
    19  myApp.debug.dylib   0x0000000106a64848 __55-[BFTask continueWithExecutor:block:cancellationToken:]_block_invoke + 88
    20  libdispatch.dylib                   0x00000001022cbec4 _dispatch_call_block_and_release + 24
    21  libdispatch.dylib                   0x00000001022cd73c _dispatch_client_callout + 16
    22  libdispatch.dylib                   0x00000001022d05a0 _dispatch_queue_override_invoke + 1320
    23  libdispatch.dylib                   0x00000001022e136c _dispatch_root_queue_drain + 372
    24  libdispatch.dylib                   0x00000001022e1f18 _dispatch_worker_thread2 + 256
    25  libsystem_pthread.dylib             0x00000001022277d8 _pthread_wqthread + 224
    26  libsystem_pthread.dylib             0x00000001022265d4 start_wqthread + 8

After debugging, this was causing the trouble: In PFObject:

+ (instancetype)object {
    PFConsistencyAssert([self conformsToProtocol:@protocol(PFSubclassing)],
                        @"Can only call +object on subclasses conforming to PFSubclassing");
    NSString *className = [(id<PFSubclassing>)self parseClassName];
    Class class = [[self subclassingController] subclassForParseClassName:className] ?: [PFObject class];
    return [class objectWithClassName:className];
}

NSString *className = [(id<PFSubclassing>)self parseClassName]; in this line className comes out to be "_Installation" because in PFInstallation there is:

+ (NSString *)parseClassName {
    return @"_Installation";
}

Also, [[self subclassingController] subclassForParseClassName:className] return nil.

Spent almost entire day on this without breaks and frustrated. All I have a doubt on is that the subclasses are not registering in Parse->Core->PFObjectSubclassingController:

- (void)registerSubclass:(Class<PFSubclassing>)kls {
    pf_sync_with_throw(_registeredSubclassesAccessQueue, ^{
        [self _rawRegisterSubclass:kls];
    });
}

which gives a nil at [[self subclassingController] subclassForParseClassName:className].

Please help! Desperately in need. Thank you!

Answer 1

We ran into the same issue. Simple fix is to register your PFObject classes at app start.

On macOS Swift, it can be done here.

func applicationDidFinishLaunching(_ aNotification: Notification) {
    // Insert code here to initialize your application

    PFInstallation.registerSubclass()
    PFUser.registerSubclass()
    PFSession.registerSubclass()
    PersonClass.registerSubclass()
}

we found it to be more convenient to do it here:

override func viewDidLoad() {
    super.viewDidLoad()

    let configuration = ParseClientConfiguration {
        $0.applicationId = Constants.PARSE_APPLICATION_ID
        $0.clientKey = Constants.PARSE_CLIENT_KEY
        $0.server = Constants.PARSE_SERVER
    }

    Parse.initialize(with: configuration)
    
    PFInstallation.registerSubclass()
    PFUser.registerSubclass()
    PFSession.registerSubclass()
    PersonClass.registerSubclass()
}

assuming your classes, like our PersonClass above, conforms to the PFObject, PFSubclassing protocols