Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."

I have an application which works fine on Xcode6-Beta1 and Xcode6-Beta2 with both iOS7 and iOS8. But with Xcode6-Beta3, Beta4, Beta5 I'm facing network issues with iOS8 but everything works fine on iOS7. I get the error "The network connection was lost.". The error is as follows:

> Error: Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." UserInfo=0x7ba8e5b0 {NSErrorFailingURLStringKey=, _kCFStreamErrorCodeKey=57, NSErrorFailingURLKey=, NSLocalizedDescription=The network connection was lost., _kCFStreamErrorDomainKey=1, NSUnderlyingError=0x7a6957e0 "The network connection was lost."}

I use AFNetworking 2.x and the following code snippet to make the network call:

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager setSecurityPolicy:policy];
manager.requestSerializer = [AFHTTPRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];

[manager POST:<example-url>
   parameters:<parameteres>
      success:^(AFHTTPRequestOperation *operation, id responseObject) {
          NSLog(@“Success: %@", responseObject);
      } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
          NSLog(@"Error: %@", error);
      }];

I tried NSURLSession but still receive the same error.

Restarting the simulator fixed the issue for me.

We had this exact error and it turned out to be an issue with the underlying HTTP implementation of NSURLRequest:

As far as we can tell, when iOS 8/9/10/11 receive an HTTP response with a Keep-Alive header, it keeps this connection to re-use later (as it should), but it keeps it for more than the timeout parameter of the Keep-Alive header (it seems to always keep the connection alive for 30 seconds.) Then when a second request is sent by the app less than 30 seconds later, it tries to re-use a connection that might have been dropped by the server (if more than the real Keep-Alive has elapsed).

Here are the solutions we have found so far:

• Increase the timeout parameter of the server above 30 seconds. It looks like iOS is always behaving as if the server will keep the connection open for 30 seconds regardless of the value provided in the Keep-Alive header. (This can be done for Apache by setting the KeepAliveTimeout option.
• You can simply disable the keep alive mechanism for iOS clients based on the User-Agent of your app (e.g. for Apache: BrowserMatch "iOS 8\." nokeepalive in the mod file setenvif.conf)
• If you don't have access to the server, you can try sending your requests with a Connection: close header: this will tell the server to drop the connection immediately and to respond without any keep alive headers. BUT at the moment, NSURLSession seems to override the Connection header when the requests are sent (we didn't test this solution extensively as we can tweak the Apache configuration)

For mine, Resetting content and settings of Simulator works. To reset the simulator follow the steps:

> iOS Simulator -> Reset Content and Settings -> Press Reset (on the > warning which will come)

The iOS 8.0 simulator runtime has a bug whereby if your network configuration changes while the simulated device is booted, higher level APIs (eg: CFNetwork) in the simulated runtime will think that it has lost network connectivity. Currently, the advised workaround is to simply reboot the simulated device when your network configuration changes.

If you are impacted by this issue, please file additional duplicate radars at http://bugreport.apple.com to get it increased priority.

If you see this issue without having changed network configurations, then that is not a known bug, and you should definitely file a radar, indicating that the issue is not the known network-configuration-changed bug.

Also have a problem with beta 5 and AFNetworking 1.3 when running on iOS 8 simulator that results in a connection error:

> Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."

The same code works fine on iOS 7 and 7.1 simulators and my debugging proxy shows that the failure occurs before a connection is actually attempted (i.e. no requests logged).

I have tracked the failure to NSURLConnection and reported bug to Apple. See line 5 in attached image:

.

Changing to use https allows connection from iOS 8 simulators albeit with intermittent errors.

Problem is still present in Xcode 6.01 (gm).

Opening Charles resolved the issue for me, which seems very strange...

> Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).

what solved the problem for me was to restart simulator ,and reset content and settings.

I was experiencing this problem while using Alamofire. My mistake was that I was sending an empty dictionary [:] for the parameters on a GET request, rather than sending nil parameters.

Hope this helps!

See pjebs comment on Jan 5 on Github.

Method1 :

if (error.code == -1005)
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
        
        dispatch_group_t downloadGroup = dispatch_group_create();
        dispatch_group_enter(downloadGroup);
        dispatch_group_wait(downloadGroup, dispatch_time(DISPATCH_TIME_NOW, 5000000000)); // Wait 5 seconds before trying again.
        dispatch_group_leave(downloadGroup);
        dispatch_async(dispatch_get_main_queue(), ^{
            //Main Queue stuff here
            [self redoRequest]; //Redo the function that made the Request.
        });
    });
    
    return;
}

Also some suggests to re-connect to the site,

i.e. Firing the POST request TWICE

Solution: Use a method to do connection to the site, return (id), if the network connection was lost, return to use the same method.

Method 2

-(id) connectionSitePost:(NSString *) postSender Url:(NSString *) URL {
     // here set NSMutableURLRequest =>  Request

    NSHTTPURLResponse *UrlResponse = nil;
    NSData *ResponseData = [[NSData alloc] init];

    ResponseData = [NSURLConnection sendSynchronousRequest:Request returningResponse:&UrlResponse error:&ErrorReturn];

     if ([UrlResponse statusCode] != 200) {

          if ([UrlResponse statusCode] == 0) {

                  /**** here re-use method ****/
                  return [self connectionSitePost: postSender Url: URL];
          }

     } else {
          return ResponseData;
     }

}

I was getting this error as well, but on actual devices rather than the simulator. We noticed the error when accessing our heroku backend on HTTPS (gunicorn server), and doing POSTS with large bodys (anything over 64Kb). We use HTTP Basic Auth for authentication, and noticed the error was resolved by NOT using the didReceiveChallenge: delegate method on NSURLSession, but rather baking in the Authentication into the original request header via adding Authentiation: Basic <Base64Encoded UserName:Password>. This prevents the necessary 401 to trigger the didReceiveChallenge: delegate message, and the subsequent network connection lost.

On 2017-01-25 Apple released a technical Q&A regarding this error:

> ## Apple Technical Q&A QA1941 > ### Handling “The network connection was lost” Errors > > A: NSURLErrorNetworkConnectionLost is error -1005 in the NSURLErrorDomain error domain, and is displayed to users as “The network connection was lost”. This error means that the underlying TCP connection that’s carrying the HTTP request disconnected while the HTTP request was in progress (see below for more information about this). In some circumstances NSURLSession may retry such requests automatically (specifically, if the request is idempotent) but in other circumstances that’s not allowed by the HTTP standards. > > https://developer.apple.com/library/archive/qa/qa1941/_index.html#//apple_ref/doc/uid/DTS40017602

I had same problem. Solution was simple, I've set HTTPBody, but haven't set HTTPMethod to POST. After fixing this, everything was fine.

I had the same problem. I don't know how AFNetworking implements https request, but the reason for me is the NSURLSession's cache problem.

After my application tracking back from safari and then post a http request, "http load failed 1005" error will appear. If I stop using "[NSURLSession sharedSession]", but to use a configurable NSURLSession instance to call "dataTaskWithRequest:" method as follow, the problem is solved.

NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
config.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
config.URLCache = nil;
self.session = [NSURLSession sessionWithConfiguration:config];

Just remember to set config.URLCache = nil;.

I had to exit XCode, delete DerivedData folder contents (~/Library/Developer/Xcode/DerivedData or /Library/Developer/Xcode/DerivedData) and exit simulator to make this work.

I have this issue also, running on an iOS 8 device. It is detailed some more here and seems to be a case of iOS trying to use connections that have already timed out. My issue isn't the same as the Keep-Alive problem explained in that link, however it seems to be the same end result.

I have corrected my problem by running a recursive block whenever I receive an error -1005 and this makes the connection eventually get through even though sometimes the recursion can loop for 100+ times before the connection works, however it only adds a mere second onto run times and I bet that is just the time it takes the debugger to print the NSLog's for me.

Here's how I run a recursive block with AFNetworking: Add this code to your connection class file

// From Mike Ash's recursive block fixed-point-combinator strategy https://gist.github.com/1254684
dispatch_block_t recursiveBlockVehicle(void (^block)(dispatch_block_t recurse))
{
    // assuming ARC, so no explicit copy
    return ^{ block(recursiveBlockVehicle(block)); };
}
typedef void (^OneParameterBlock)(id parameter);
OneParameterBlock recursiveOneParameterBlockVehicle(void (^block)(OneParameterBlock recurse, id parameter))
{
    return ^(id parameter){ block(recursiveOneParameterBlockVehicle(block), parameter); };
}

Then use it likes this:

+ (void)runOperationWithURLPath:(NSString *)urlPath
            andStringDataToSend:(NSString *)stringData
                    withTimeOut:(NSString *)timeOut
     completionBlockWithSuccess:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                        failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure
{
    OneParameterBlock run = recursiveOneParameterBlockVehicle(^(OneParameterBlock recurse, id parameter) {
        // Put the request operation here that you want to keep trying
        NSNumber *offset = parameter;
        NSLog(@"--------------- Attempt number: %@ ---------------", offset);
        
        MyAFHTTPRequestOperation *operation =
            [[MyAFHTTPRequestOperation alloc] initWithURLPath:urlPath
            andStringDataToSend:stringData
            withTimeOut:timeOut];
        
        [operation setCompletionBlockWithSuccess:
            ^(AFHTTPRequestOperation *operation, id responseObject) {
                success(operation, responseObject);
            }
            failure:^(AFHTTPRequestOperation *operation2, NSError *error) {
                if (error.code == -1005) {
                    if (offset.intValue >= numberOfRetryAttempts) {
                        // Tried too many times, so fail
                        NSLog(@"Error during connection: %@",error.description);
                        failure(operation2, error);
                    } else {
                        // Failed because of an iOS bug using timed out connections, so try again
                        recurse(@(offset.intValue+1));
                    }
                } else {
                    NSLog(@"Error during connection: %@",error.description);
                    failure(operation2, error);
                }
            }];
        [[NSOperationQueue mainQueue] addOperation:operation];
    });
    run(@0);
}

You'll see that I use a AFHTTPRequestOperation subclass but add your own request code. The important part is calling recurse(@offset.intValue+1)); to make the block be called again.

I was getting the error on an iOS 7 device when I was using Xcode 6.2 beta.

Switching back from Xcode 6.2 beta to 6.1.1 fixed the issue, at least on an iOS 7 device.

If the problem is occurring on a device, check if traffic is going through a proxy (Settings > Wi-Fi > (info) > HTTP Proxy). I had my device setup to use with Charles, but forgot about the proxy. Seems that without Charles actually running this error occurs.

If anyone is getting this error while uploading files to a backend server, make sure the receiving server has a maximum content size that is allowable for your media. In my case, NGINX required a higher client_max_body_size. NGINX would reject the request before the uploading was done so no error code came back.

Got the issue for months, and finally discovered that when we disable DNSSEC on our api domain, everything was ok :simple_smile:

I was connecting via a VPN. Disabling the VPN solved the problem.

I was hitting this error when passing an NSURLRequest to an NSURLSession without setting the request's HTTPMethod.

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:urlComponents.URL];

> Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."

Add the HTTPMethod, though, and the connection works fine

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:urlComponents.URL];
[request setHTTPMethod:@"PUT"];

Test if you can request from other apps (like safari). If not might be something on your computer. In my case I had this problem with Avast Antivirus, which was blocking my simulators request (don't ask me why).

Whenever got error -1005 then need to call API Again.

AFHTTPRequestOperationManager *manager = 
[AFHTTPRequestOperationManager manager];
[manager setSecurityPolicy:policy];
manager.requestSerializer = [AFHTTPRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];

[manager POST:<example-url>
   parameters:<parameteres>
    success:^(AFHTTPRequestOperation *operation, id responseObject) {
      NSLog(@“Success: %@", responseObject);
  } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
      NSLog(@"Error: %@", error);
      if (error.code == -1005) {
          // Call method again... 
       }
  }];

You need to Add your code to call function again. MakeSure that you were call method once otherwise its call recursive loop.

I was facing the same issue, I have enabled Network Link Conditioner for slow network testing for the app. That was creating this error some times, When i have disabled it from Settings > Developer > Network Link Conditioner, it solved my problem.

Hope this help someone.

On top of all the answers i found one nice solution. Actually The issue related to network connection fail for iOS 12 onword is because there is a bug in the iOS 12.0 onword. And it Yet to resolved. I had gone through the git hub community for AFNetworking related issue when app came from background and tries to do network call and fails on connection establish. I spend 3 days on this and tries many things to get to the root cause for this and found nothing. Finally i got some light in the dark when i red this blog https://github.com/AFNetworking/AFNetworking/issues/4279

It is saying that there is a bug in the iOS 12. Basically you cannot expect a network call to ever complete if the app os not in foreground. And due to this bug the network calls get dropped and we get network fails in logs.

My best suggestion to you is provide some delay when your app are coming from background to foreground and there is network call. Make that network call in the dispatch async with some delay. You'll never get network call drop or connection loss.

Do not wait for Apple to let this issue solve for iOS 12 as its still yet to fix. You may go with this workaround by providing some delay for your network request being its NSURLConnection, NSURLSession or AFNetworking or ALAMOFIRE. Cheers :)

In my case it was because i was connecting to HTTP and it was running on HTTPS

I was having this issue for the following reason.

TLDR: Check if you are sending a GET request that should be sending the parameters on the url instead of on the NSURLRequest's HTTBody property.

==================================================

I had mounted a network abstraction on my app, and it was working pretty well for all my requests.

I added a new request to another web service (not my own) and it started throwing me this error.

I went to a playground and started from the ground up building a barebones request, and it worked. So I started moving closer to my abstraction until I found the cause.

My abstraction implementation had a bug: I was sending a request that was supposed to send parameters encoded in the url and I was also filling the NSURLRequest's HTTBody property with the query parameters as well. As soon as I removed the HTTPBody it worked.

I was receiving this error and also notices that the application Postman was also falling but was working in app Advanced Rest Client (ARC) and working in Android. So i had to install Charles to debug the communication and I notices that response code was -1. The problem was that REST programmer forgot to return response code 200.

I hope that this help other developers.

Restarting the computer fixed the issue for me with Xcode9.1. I had restarted the simulator and Xcode, it doesn't work.

I faced the same issue while calling using my company's server from iOS 12 app with a physical device. The problem was that the server hard disk was full. Freeing space in the server solved the problem.

I found the same error in another situation I think due to a timeout not parametrizable through the standard Networking API provided by Apple (URLSession.timeoutIntervalForRequest and URLSession.timeoutIntervalForResource). Even there.. made server answer faster solved the problem

This might be a problem of the parameter that you are passing to request body. I was also facing the same issue. But then I came across CMash's answer here https://stackoverflow.com/a/34181221/5867445 and I changed my parameter and it works.

Issue in a parameter that I was passing is about String Encoding.

Hope this helps.

My problem was on the server. I was using Python's BaseHTTPRequestHandler class and I wasn't sending a body in the response. My problem was solved when I put an empty body like the following.

def do_POST(self):
    content_len = int(self.headers.get('Content-Length'))
    post_body = self.rfile.read(content_len)
    msg_string = post_body.decode("utf-8")
    msg_json = json.loads(msg_string)
    self.send_response(200)
    self.end_headers() #this and the following lines were missing
    self.wfile.write(b'')