Не удалось завершить операцию nsurlerrordomain ошибка 999

asked Apr 18, 2013 at 2:27

answered Jul 4, 2019 at 10:31

In addition to what Ramon wrote, there is a third possible reason when receiving a NSURLErrorDomain -999 cancelled:

You cancelled the task while it was executing either by calling .cancel() on the datatask object or because you used .invalidateAndCancel() on the session object. If you are creating a custom session with a delegate, you should call .invalidateAndCancel() or .finishTasksAndInvalidate() to resolve the strong reference between the session and its delegate, as mentioned in the Apple Developer Documentation:

The session object keeps a strong reference to the delegate until your app exits or explicitly invalidates the session. If you don’t invalidate the session, your app leaks memory until it exits.

If you are wondering about this logging behaviour, I found the following explanation in the Apple Developer forums:

By way of explanation, back in iOS 10 we introduced a new logging system-wide logging architecture (watch WWDC 2016 Session 721 Unified Logging and Activity Tracing for the details) and lots of subsystem, including CFNetwork, are in the process of moving over to that. Until that move is fully finished you’re going to encounter some weird edge cases like this one.

answered Aug 24, 2019 at 7:56

Our company’s app has many -999 error in iOS. I have searched around, find the reason has two, like the network task has been dealloc or the certificate isn’t valid. But I have checked our code, these two aren’t possible. I am using Alamofire
which is using URLSession. Luckily, our company’s android app’s network is normal. So we check the difference. We found the http request from iOS is Http2.0, while android is Http1.1. So we force the backend http support version down to http1.1, then -999 error count descends!!!

I think there maybe some bug in Apple’s URLSession. Check the link New NSURLSession for every DataTask overkill? for some detail thoughts

answered Jul 26, 2019 at 3:47

Please check If you call cancel() on URLSessionDataTask to fix

NSURLErrorDomain Code=-999 "cancelled"

answered Oct 25, 2020 at 17:57

answered Sep 12, 2019 at 19:39

For my Cordova project (or similar), turns out it was a plugin issue. Make sure you’re not missing any plugins and make sure they’re installed properly without issue.

Easiest way to verify this is simply to start fresh by recreating the Cordova project (cordova create <path>) along with the required platforms (cordova platform add <platform name>) and add each plugin with the verbose flag (—verbose) so that you can see if anything went wrong in the console log while the plugin is being downloaded, added to project and installed for each platform (cordova plugin add cordova-plugin-device --verbose)

Recap:
cordova create <path>
cordova platform add <platform name>
cordova plugin add cordova-plugin-device --verbose

answered Oct 1, 2019 at 8:03

For my case, I used an upload task post that did not need body contents:

// The `from: nil` induces error "cancelled" code -999
let task = session.uploadTask(with: urlRequest, from: nil, completionHandler: handler)

The fix is to use zero byte data instead of nil,

let task = session.uploadTask(with: urlRequest, from: Data(), completionHandler: handler)

The framework documentation doesn’t specify why the from bodyData is an optional type, or what happens when it is nil.

answered Aug 11, 2021 at 17:43

We solved this problem by reloading the web view when it failed loading.

extension WebViewController: WKNavigationDelegate {
    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
        webView.reload()
    }
}

answered Mar 21, 2022 at 9:39

Andrea BozzaAndrea Bozza

1,3742 gold badges12 silver badges31 bronze badges

A couple of observations:

1. Error -999 is kCFURLErrorCancelled.

2. If you are using NSURLSessionDownloadTask, you can download those in the background using background session configuration, e.g.

   NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:kBackgroundIdentifier];
   NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
   

   If not using background session (e.g. you have to use data task, for example), you can use beginBackgroundTaskWithExpirationHandler to request a little time for the app the finish requests in the background before the app terminates.

3. Note, when using background sessions, your app delegate must respond to handleEventsForBackgroundURLSession, capturing the completion handler that it will call when appropriate (e.g., generally in URLSessionDidFinishEventsForBackgroundURLSession).

4. How did you «terminate the app»? If you manually kill it (by double tapping on home button, holding down on icon for running app, and then hitting the little red «x»), that will not only terminate the app, but it will stop background sessions, too. Alternatively, if the app crashes or if it is simply jettisoned because foreground apps needed more memory, the background session will continue.

   Personally, whenever I want to test background operation after app terminates, I have code in my app to crash (deference nil pointer, like Apple did in their WWDC video introduction to NSURLSession). Clearly you’d never do that in a production app, but it’s hard to simulate the app being jettisoned due to memory constraints, so deliberately crashing is a fine proxy for that scenario.

answered Oct 15, 2014 at 16:40

I use this configuration

- (NSURLSession *)backgroundSession
{
/*
 Using disptach_once here ensures that multiple background sessions with the same identifier are not created in this instance of the application. If you want to support multiple background sessions within a single process, you should create each session with its own identifier.
 */
    static NSURLSession *session = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration backgroundSessionConfiguration:@"com.example.apple-samplecode.SimpleBackgroundTransfer.BackgroundSession"];
        session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
    });
    return session;
}

let me explain what i mean with «terminate the app» (in ios8):

• double tap on home button
• swipe on my open app.
• app disappear from open app list
• relaunch app.

When i reopen the app i enter into callback with error

The operation couldn't be completed. (NSURLErrorDomain error -999.)

There is something that i can’t understand. This behaviour make me crazy!

answered Oct 15, 2014 at 21:38

Ошибка зарегистрирована в Mac Developer Library (iOS docs)

Соответствующий сегмент из документации будет:

Коды ошибок системы загрузки URL

Эти значения возвращаются как свойство кода ошибки объекта NSError с доменом «NSURLErrorDomain».

enum
{
   NSURLErrorUnknown = -1,
   NSURLErrorCancelled = -999,
   NSURLErrorBadURL = -1000,
   NSURLErrorTimedOut = -1001,

Как вы можете видеть ; -999 вызвано ErrorCancelled. Это означает: выполняется другой запрос до завершения предыдущего запроса.

Я не использовал API Facebook Corona SDK, но я столкнулся с этой проблемой при использовании Alamofire, secondRequest всегда отменяют исполнение с ошибкой -999, согласно сообщениям, которые я нашел в Интернете, причина в том, что session свойство deinit до завершения работы async, так как оно выходит за рамки, я, наконец, решил эту проблему с помощью свойства deinit сеанса вручную, поэтому компилятор не будет деактивировать его в неправильном положении:

class SessionManager {
    var session:SessionManager?

    init() {
        self.session = SessionManager(configuration:URLSessionConfiguration.ephemeral)
    }
    private func firstRequest() {
        guard let session = self.session else {return}
        session.request(request_url).responseData {response in
            if let data=response.data {
                self.secondRequest()
            }
    }
    private func secondRequest() {
        guard let session = self.session else {return}
        session.request(request_url).responseData {response in
            if let data=response.data {
                self.secondRequest()
            }
            //session will no longer be needed, deinit it
            self.session = nil
    }

    }

hjpotter92 абсолютно прав, я просто хочу предоставить решение для своего дела. Надеюсь, это полезно и вам. Вот моя ситуация:

На странице входа в систему> нажмите в журнале> всплывающее диалоговое окно загрузки> журнал вызовов в службе> отменить диалог> нажать другой экран> вызвать другую услугу -> вызвать ошибку -999

Чтобы исправить это, я установил задержку между отклонением диалога и нажатием нового экрана:

    [indicatorAlert dismissWithClickedButtonIndex:0 animated:YES];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.01 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
                [self performSegueWithIdentifier:@"HomeSegue" sender:nil];
            });

Странно, что эта проблема возникает только на iOS 7.

This came up when trying to set Photos to connect with iCloud on a Mac (Monterey)

what does it mean and how do I fix it?

Thank you for that.

I had followed that procedure so I undid it, rebooted and did it again.

that cleared the error.