... and I managed to fix most issues coming out, but for a specific issue in an class adopting a protocol; basically it is a support class to be used by the view controller and so I wanted to keep it in background, so I created a new actor and I wanted to use it for this protocol and adopting classes. Yet I came out with a host of errors I have no idea about how to cope with: :

This is the full logging: libsystem_kernel.dylib`__pthread_kill: 0x2502f71c8 <+0>: mov x16, #0x148 ; =328 0x2502f71cc <+4>: svc #0x80 -> 0x2502f71d0 <+8>: b.lo 0x2502f71f0 ; <+40> 0x2502f71d4 <+12>: pacibsp 0x2502f71d8 <+16>: stp x29, x30, [sp, #-0x10]! 0x2502f71dc <+20>: mov x29, sp 0x2502f71e0 <+24>: bl 0x2502f2900 ; cerror_nocancel 0x2502f71e4 <+28>: mov sp, x29 0x2502f71e8 <+32>: ldp x29, x30, [sp], #0x10 0x2502f71ec <+36>: retab 0x2502f71f0 <+40>: ret

This is the code I use: @MainActor func picker()->UIViewController{ let pickerController = MPMediaPickerController(mediaTypes: .music) print(pickerController) pickerController.showsCloudItems=true pickerController.prompt = NSLocalizedString("Add pieces to queue", comment:""); pickerController.allowsPickingMultipleItems=true; pickerController.delegate=MPMusicPlayerControllerSingleton.sharedController(); return pickerController } MainActor @IBAction func handleBrowserTapped(_ sender: AnyObject){ if let pickerController=contentProvider?.picker(){ self.present(pickerController, animated:true, completion:nil) } } And this his is the crash log: *** Assertion failure in -[MPMediaPickerController_Appex requestRemoteViewController], MPMediaPickerController.m:523 *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'remoteViewController cannot be nil -- process will crash inserting in hierarchy. We likely got a nil remoteViewController because Music is crashing.' *** First throw call stack: (0x1869cac70 0x183499224 0x1844f9f50 0x1a6c6a060 0x18d45518c 0x18d4cd410 0x103354544 0x10336dccc 0x10338f748 0x103364204 0x103364144 0x186957a64 0x1868e5288 0x1868e41d0 0x22bde7498 0x18c5a5ca0 0x18c510254 0x18c71ce90 0x103854340 0x1038542b0 0x103854430 0x1834f1c1c) libc++abi: terminating due to uncaught exception of type NSException *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'remoteViewController cannot be nil -- process will crash inserting in hierarchy. We likely got a nil remoteViewController because Music is crashing.'