what cause error NSNetServicesErrorCode = "-72000"?

Question

i create a simple browser that can load a local file using UIWebview. At first,when i try to preview a html file, the uiwebview can load the source file and preview it. But after i minimize the app (the app enter background), and then open the app again, i've got this error :

Error Dict: {
    NSNetServicesErrorCode = "-72000";
    NSNetServicesErrorDomain = 10;
}

and after that, the uiwebview can not load the source file, when i log the error in (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error, it shows this message :

Error Domain=NSURLErrorDomain Code=-1004 "Could not connect to the server." UserInfo=0x53d610 {NSErrorFailingURLStringKey=http://localhost:9898/local/a.html?83C66B33-874C-41A7-BBF5-78D1615512DF, NSErrorFailingURLKey=http://localhost:9898/local/a.html?83C66B33-874C-41A7-BBF5-78D1615512DF, NSLocalizedDescription=Could not connect to the server., NSUnderlyingError=0x5ccaa0 "Could not connect to the server."}

the app isn't crash, but the spinning indicator is never stop.

could somebody tell me what cause this case? and how to solved it?

Thank you :)

If this happens on a Mac, it could mean the App is Sandboxed (you can check that in the entitlement file). Just for anyone else stumbling upon this. — Sergiu Todirascu, Apr 10 '19 at 15:31

score 7 · Answer 1 · answered Nov 10 '15 at 14:24

If you look inside the NSNetServices header, you'll see the following enum that explains each error:

typedef NS_ENUM(NSInteger, NSNetServicesError) {

/* An unknown error occured during resolution or publication.
*/
    NSNetServicesUnknownError = -72000L,

/* An NSNetService with the same domain, type and name was already present when the publication request was made.
*/
    NSNetServicesCollisionError = -72001L,

/* The NSNetService was not found when a resolution request was made.
*/
    NSNetServicesNotFoundError  = -72002L,

/* A publication or resolution request was sent to an NSNetService instance which was already published or a search request was made of an NSNetServiceBrowser instance which was already searching.
*/
    NSNetServicesActivityInProgress = -72003L,

/* An required argument was not provided when initializing the NSNetService instance.
*/
    NSNetServicesBadArgumentError = -72004L,

/* The operation being performed by the NSNetService or NSNetServiceBrowser instance was cancelled.
*/
    NSNetServicesCancelledError = -72005L,

/* An invalid argument was provided when initializing the NSNetService instance or starting a search with an NSNetServiceBrowser instance.
*/
    NSNetServicesInvalidError = -72006L,

/* Resolution of an NSNetService instance failed because the timeout was reached.
*/
    NSNetServicesTimeoutError = -72007L,

};

You're getting a service collision error, which means that a net service with the same domain, type, and name are already publishing their service on your network.

In general, I always consult the header file for error codes. They're nearly always assigned by an enum value, and the enum usually has a much more descriptive name than the number used.

`-72000` is in fact the "unknown" error, not the collision error. — Lily Ballard, Apr 16 '18 at 06:21

score 2 · Answer 2 · answered Jun 28 '12 at 23:10

2

The problem seems to be the host you are trying to connect to: http://localhost:9898/local/[..]

Localhost on your computer is your computer, localhost on your ipad is your ipad - for testing use resolvable domain name or ip address.

answered Jun 28 '12 at 23:10

c2h5oh

4,492
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I get the same error code, while connecting to some local IP. Or rather push my Server to the local network and access it via 192.x.y.z. Therefor the bounty. – Bersaelor Jun 29 '12 at 13:20
Are you sure ipad can access that url? try typing it in ipads browser address bar just to be certain. – c2h5oh Jun 29 '12 at 15:22
I can't access it from any device in the local network, once this error occurs. Usually I can publish the web service without problems, then it's accessible from any device (iPad, Macbook, Android Phone, Windows PC, whatever). But sometimes I get this error and was interested to know what the error code is trying to tell me. – Bersaelor Jun 29 '12 at 15:54
If you can't access it then the problem is server-side. Error code -72000 is "Unknown error", so all it tells you is that is isn't any of the usual stuff, but doesn't go into detail. – c2h5oh Jun 29 '12 at 16:42
Yes, of course it's server-side thats the point. The iPhone is serving the web-page to devices in the local network. I'm publishing the server and sometimes, while publishing I get the error the question-asker had too :/ – Bersaelor Jun 29 '12 at 16:59
As I said this error message gives you virtually no info as it is described in docs as "unknown error", so it's "I can't connect and I don't even know why, WTF" and that sadly is the most precise answer here. – c2h5oh Jun 29 '12 at 17:50

score 0 · Answer 3 · answered Jun 15 '20 at 00:11

0

Sergiu Todirascu's comment in the question solved it for me. The Mac Sandbox was causing this, I had to turn on Networking, in my case Incoming and Outgoing network checkboxes, in the entitlements tab. Creating an answer so it is more easy to see.

answered Jun 15 '20 at 00:11

possen

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Is this relevant for iOS? – User Jul 14 '20 at 14:07

what cause error NSNetServicesErrorCode = "-72000"?

3 Answers3