[0.76] FAULT: RCTAppDelegate::bundleURL not implemented

[DanielSRS]

Environment

react-native -v: 0.76.3
npm ls react-native-macos: react-native-macos@0.76.4
node -v: v21.7.1
npm -v: 10.5.0
yarn --version: 4.5.3
xcodebuild -version: Xcode 16.1

Steps to reproduce the bug

1. Create a react-native-macos project (0.76.4, 0.76.3 or 0.76.0)
2. Open it in xcode and run (npx react-native run-macos builds, but no window or error is shown)

Expected Behavior

The app opens with a new window

Actual Behavior

The app do not open, and xcode shows that there was an error:

Can't find or decode disabled use cases
An uncaught exception was raised
Subclasses must implement a valid getBundleURL method
(
	0   CoreFoundation                      0x00000001870e4300 __exceptionPreprocess + 176
	1   libobjc.A.dylib                     0x0000000186bcacd8 objc_exception_throw + 88
	2   CoreFoundation                      0x00000001870e41f0 +[NSException exceptionWithName:reason:userInfo:] + 0
	3   AwesomeProject.debug.dylib          0x00000001060deaf0 -[RCTAppDelegate bundleURL] + 52
	4   AwesomeProject.debug.dylib          0x00000001060df5d8 __42-[RCTAppDelegate createRCTRootViewFactory]_block_invoke + 44
	5   AwesomeProject.debug.dylib          0x00000001060e9278 -[RCTRootViewFactory bundleURL] + 56
	6   AwesomeProject.debug.dylib          0x00000001060e8b08 __38-[RCTRootViewFactory createReactHost:]_block_invoke.124 + 40
	7   AwesomeProject.debug.dylib          0x00000001062518a0 -[RCTHost start] + 88
	8   AwesomeProject.debug.dylib          0x00000001060e8930 -[RCTRootViewFactory createReactHost:] + 424
	9   AwesomeProject.debug.dylib          0x00000001060e8700 -[RCTRootViewFactory createReactHostIfNeeded:] + 144
	10  AwesomeProject.debug.dylib          0x00000001060e72bc -[RCTRootViewFactory viewWithModuleName:initialProperties:launchOptions:] + 280
	11  AwesomeProject.debug.dylib          0x00000001060de050 -[RCTAppDelegate loadReactNativeWindow:] + 176
	12  AwesomeProject.debug.dylib          0x00000001060ddf2c -[RCTAppDelegate applicationDidFinishLaunching:] + 620
	13  AwesomeProject.debug.dylib          0x0000000105bd3e30 -[AppDelegate applicationDidFinishLaunching:] + 128
	14  CoreFoundation                      0x0000000187066800 __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
	15  CoreFoundation                      0x00000001870f766c ___CFXRegistrationPost_block_invoke + 88
	16  CoreFoundation                      0x00000001870f75b4 _CFXRegistrationPost + 436
	17  CoreFoundation                      0x000000018703543c _CFXNotificationPost + 732
	18  Foundation                          0x00000001881ddb14 -[NSNotificationCenter postNotificationName:object:userInfo:] + 88
	19  AppKit                              0x000000018aba4614 -[NSApplication _postDidFinishNotification] + 284
	20  AppKit                              0x000000018aba43c4 -[NSApplication _sendFinishLaunchingNotification] + 172
	21  AppKit                              0x000000018aba2824 -[NSApplication(NSAppleEventHandling) _handleAEOpenEvent:] + 500
	22  AppKit                              0x000000018aba242c -[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] + 488
	23  Foundation                          0x000000018820679c -[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] + 316
	24  Foundation                          0x0000000188206594 _NSAppleEventManagerGenericHandler + 80
	25  AE                                  0x000000018e554134 _AppleEventsCheckInAppWithBlock + 13904
	26  AE                                  0x000000018e553a58 _AppleEventsCheckInAppWithBlock + 12148
	27  AE                                  0x000000018e54cfa4 aeProcessAppleEvent + 488
	28  HIToolbox                           0x00000001923fdc4c AEProcessAppleEvent + 68
	29  AppKit                              0x000000018ab9bd00 _DPSNextEvent + 1420
	30  AppKit                              0x000000018b4dbe0c -[NSApplication(NSEventRouting) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 688
	31  AppKit                              0x000000018ab8eae0 -[NSApplication run] + 480
	32  AppKit                              0x000000018ab65364 NSApplicationMain + 888
	33  AwesomeProject.debug.dylib          0x0000000105bd3da4 __debug_main_executable_dylib_entry_point + 36
	34  dyld                                0x0000000186c08274 start + 2840
)
FAULT: RCTAppDelegate::bundleURL not implemented: Subclasses must implement a valid getBundleURL method; (user info absent)
NSBundle file:///System/Library/PrivateFrameworks/MetalTools.framework/ principal class is nil because all fallbacks have failed
WARNING: Secure coding is automatically enabled for restorable state! However, not on all supported macOS versions of this application. Opt-in to secure coding explicitly by implementing NSApplicationDelegate.applicationSupportsSecureRestorableState:.

Reproducible Demo

No response

Additional context

I as able to fix it with a patch suggested in an older issue:

Just documenting for anyone on v0.74. When generating a fresh react-native-macos@0.74.15 app, the following error will be raised on startup:

RCTAppDelegate::bundleURL not implemented
Subclasses must implement a valid getBundleURL method

It can be fixed, as suggested above, by applying the following patch to AppDelegate.mm:

  - (NSURL *)sourceURLForBridge:(RCTBridge *)bridge
  {
- #if DEBUG
-   return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index"];
- #else
-   return [[NSBundle mainBundle] URLForResource:@"main" withExtension:@"jsbundle"];
- #endif
+   return [self bundleURL];
  }
+
+ - (NSURL *)bundleURL
+ {
+ #if DEBUG
+   return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index"];
+ #else
+   return [[NSBundle mainBundle] URLForResource:@"main" withExtension:@"jsbundle"];
+ #endif
+ }

Originally posted by @shirakaba in #2164

With these changes the app builds and opens successfully

[Saadnajmi]

Thanks for the report and fix! Any chance you'd be willing to submit a PR for this? Otherwise I'll try to get to it next week.

[DanielSRS]

Certainly! just opened #2309