Firebase Storage cryptic message: libc++abi.dylib: terminating with uncaught exception of type NSException

Question

ERROR: libc++abi.dylib: terminating with uncaught exception of type NSException

I am struggling to decipher this cryptic error message when I try to upload an image to Firebase Storage and then create a user on Firebase Database using the url of the image uploaded in addition to other user attributes.

The app crashes and shows the console output below, the line --- 4 does not print to the console so it indicates that the .putData call is not working.

Any help would be appreciated.

Console output:

Inside createFirebaseUser()
--- 1
--- 2
--- 3
libc++abi.dylib: terminating with uncaught exception of type NSException

Function:

    fileprivate func createFirebaseUser(firebaseUserComplete: @escaping (_ status: Bool) -> ()){
        print("Inside createFirebaseUser()")

        let fileName = UUID().uuidString
        print("--- 1")
        guard let profilePic = self.profilePic else { return }
        print("--- 2")
        guard let uploadData = UIImageJPEGRepresentation(profilePic, 0.5) else { return }
        print("--- 3")

        StorageService.run.REF_STORAGE_USERSPICS.child(fileName).putData(uploadData, metadata: nil) { (metadata, error) in
            if let error = error {
                print("There is an error with putData: \(error)")
                return
            }//end if-let

            print("--- 4")
            StorageService.run.REF_STORAGE_USERSPICS.child(fileName).downloadURL(completion: { (url, error) in
                guard let profilePicURL = url?.absoluteString else {
                    print("failed to get image URL: ", error!)
                    return
                }//end guard-let

                guard let uid = Auth.auth().currentUser?.uid else { return }

                let signupTimeRef = String(Date.timeIntervalSinceReferenceDate)

                let prefs = ["women": 0,
                             "men": 0,
                             "minAge": 18,
                             "maxAge": 49]

                //building the values for the dictionary
                let dictionaryValues = ["name": self.name!,
                                        "email": self.email!,
                                        "profilePictureURL": profilePicURL,
                                        "firstName": self.firstName!,
                                        "lastName": self.lastName!,
                                        "gender": self.gender!,
                                        "birthday": self.birthday!,
                                        "signupTime": signupTimeRef,
                                        "discoverable": true,
                                        "online": true,
                                        "lastOnline": ServerValue.timestamp(),
                                        "discoveryPrefs": prefs] as [String : Any]

                //combining both uid and dictionary values in readiness for user creation
                let values = [uid: dictionaryValues]

                //creating the user and passing its values
                DataService.run.REF_USERS.updateChildValues(values, withCompletionBlock: { (error, reference) in
                    if let error = error {
                        firebaseUserComplete(false)
                        print (error)
                        return
                    }
                    firebaseUserComplete(true)
                    print ("Successfully saved user into Firebase database.")
                })// end DataService.run.REF_USERS.updateChildValues


            })//end .downloadURL

        }////end .putData

 }

Full error log:

2018-08-14 21:56:25.069011+0930 vipeeps[15149:7547021] *** Assertion failure in -[FIRStorageUploadTask enqueue], /Users/.../Pods/FirebaseStorage/Firebase/Storage/FIRStorageUploadTask.m:73
2018-08-14 21:56:25.071681+0930 vipeeps[15149:7547021] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Upload attempting to execute on non main queue! Please only execute this method on the main queue.'
*** First throw call stack:
(0x183b3ad8c 0x182cf45ec 0x183b3abf8 0x18452afa0 0x100428098 0x1004217c0 0x100256640 0x100255d8c 0x100255f98 0x1840c9dbc 0x1840e2adc 0x184562e88 0x1844a48d0 0x1844a3cac 0x1050e119c 0x1050ed7cc 0x1050e119c 0x1050ed7cc 0x1050ed6b0 0x184564750 0x1050e119c 0x1050ee454 0x1050ecd44 0x1050f27c8 0x1050f2500 0x18375ffac 0x18375fb08)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

add your code inside a main thread hope it's help

 DispatchQueue.main.async {
      //Your code
 }