com.apple.WebKit.WebContent drops 113 error: Could not find specified service

Question

I am using WKWebView for viewing custom HTML.

Regardless of HTML content, when testing on real device, I receive the following error Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service in 29 sec after WKWebView content loaded, sometimes I even receive this error twice. Clearly, it is a configuration issue. I have checked cookies as proposed in Could not signal service com.apple.WebKit.WebContent, however it doesn't help
Another question is whether there exist a list of all error codes that might pop up in WKWebView

Hi, I'm getting this error when using a project generated by Unity, specifically while trying to initialize the ads package. Does anyone know what might be causing this? — Figwig, Oct 22 '19 at 16:51

score 38 · Answer 1 · edited May 24 '18 at 10:45

38

Finally, solved the problem above. I was receiving errors

Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service

Since I have not added WKWebView object on the view as a subview and tried to call -loadHTMLString:baseURL: on the top of it. And only after it was successfully loaded I was adding it to view's subviews - which was totally wrong. The correct solution for my problem is:

1. Add WKWebView object to view's subviews array

2. Call -loadHTMLString:baseURL: for recently added WKWebView

edited May 24 '18 at 10:45

Boris Y.

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answered Jun 19 '17 at 06:06

Ievgen

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@Nikita, did it help you? Please, share your exp and env. conditions. I am asking since i was planning to remove this comment since it doesn't solve 100% cases why this error can pop up... – Ievgen Jul 11 '17 at 13:09
1

the log itself happens every time in different cases; I have not found consistent pattern for the log; but the fact of webview addition to the view hierarchy does help to load all of the requests. I had exactly the same case - was not adding a webview to view until it loads; so now I add it to keywindow as hidden in order that it be in view hierarchy, and then, when it loads, I add it to the place it supposed to be and disable hidden property; – Nikita Jul 12 '17 at 13:53
11

I'm doing what you said in the right order, but I still I get the error. I noticed that the moment it happens seems quite random to me... Like sometimes it happens after I have already dismissed the VC that had the WebView, and some other times it happens when I load it... Have you already figured anything else out? – Andreza Cristina da Silva Oct 06 '17 at 19:36
Thank you this is what I was doing as well and this completely fixes the problem! – Austin Oct 19 '18 at 16:57
Please can i do that " Add WKWebView object to view's subviews array" from a capacitor app (ionic 5) – valik Dec 14 '20 at 16:25

score 17 · Answer 2 · answered Dec 14 '17 at 11:28

17

I too faced this problem when loading an 'http' url in WKWebView in iOS 11, it is working fine with https.

What worked for me was setting App transport setting in info.pist file to allow arbitary load.

<key>NSAppTransportSecurity</key>
    <dict>
        <!--Not a recommended way, there are better solutions available-->
        <key>NSAllowsArbitraryLoads</key>
        <true/>
    </dict>

answered Dec 14 '17 at 11:28

Asad Khan

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This would require a justification in App Store submission as per: https://developer.apple.com/documentation/bundleresources/information_property_list/nsapptransportsecurity/nsallowsarbitraryloads – zaitsman Jul 31 '19 at 05:01

yusuke024 · Answer 3 · 2018-07-13T18:08:57.513

Maybe it's an entirely different situation, but I always got WebView[43046:188825] Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service when opening a webpage on the simulator while having the debugger attached to it. If I end the debugger and opening the app again the webpage will open just fine. This doesn't happen on the devices.

After spending an entire work-day trying to figure out what's wrong, I found out that if we have a framework named Preferences, UIWebView and WKWebView will not be able to open a webpage and will throw the error above.

To reproduce this error just make a simple app with WKWebView to show a webpage. Then create a new framework target and name it Preferences. Then import it to the main target and run the simulator again. WKWebView will fail to open a webpage.

So, it might be unlikely, but if you have a framework with the name Preferences, try deleting or renaming it.

Also, if anyone has an explanation for this please do share.

BTW, I was on Xcode 9.2.

I just encountered this and simply running in the simulator without an Xcode debugging session made it go away. There was no Preferences framework or anything else, but it did look like it was related to cookies/`localStorage` issue in the `WKWebView`. — Echelon, Aug 31 '18 at 10:03

score 9 · Answer 4 · answered Oct 07 '17 at 12:54

9

I got this error loading a http:// URL where the server replied with a redirect to https. After changing the URL I pass to WKWebView to https://... it worked.

answered Oct 07 '17 at 12:54

Markus

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Thanks! I was debugging and left off the "s" on the test URL i was using.. this fixed it for me... – Don Apr 27 '20 at 01:36
in my case http:// also works – deepOcean Dec 14 '21 at 09:56

score 6 · Answer 5 · edited Aug 13 '19 at 15:07

6

I had this problem I iOS 12.4 when calling evaluateJavascript. I solved it by wrapping the call in DispatchQueue.main.async { }

edited Aug 13 '19 at 15:07

Amit Joshi

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answered Aug 13 '19 at 14:48

John Popham

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where can i write.. i trid but not playing video – Maulik shah Dec 17 '20 at 18:05
DispatchQueue.main.async { self.wkWebView.loadHTMLString("Long Live the KING

", baseURL: nil) } – ittgung Dec 24 '20 at 08:37

Abhishek Mitra · Answer 6 · 2018-03-22T09:48:57.593

3

SWIFT

Well I did this in the following order and didn't get any error like Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service after that, following code might help you too.

webView = WKWebView(frame: self.view.frame)
self.view.addSubview(self.view.webView)
webView.navigationDelegate = self
webView.loadHTMLString(htmlString, baseURL: nil)

Do as order.

Thanks

edited Mar 22 '18 at 09:48

answered Mar 21 '18 at 07:43

Abhishek Mitra

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score 2 · Answer 7 · answered Oct 09 '18 at 21:21

2

In my case I was launching a WKWebView and displaying a website. Then (within 25 seconds) I deallocated the WKWebView. But 25-60 seconds after launching the WKWebView I received this "113" error message. I assume the system was trying to signal something to the WKWebView and couldn't find it because it was deallocated.

The fix was simply to leave the WKWebView allocated.

answered Oct 09 '18 at 21:21

Peter B. Kramer

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That doesn't seem like a clean solution. I would not like my WKWebView to still exist even after i obviously don't need it anymore because it's using resources and costing a lot of memory. – dedda1994 Sep 03 '19 at 10:00
2

I think such thing is called memory leak. – Mateusz Nov 03 '19 at 17:40
Memory leak, perhaps - but it drove me crazy. I alloc/init only one WKWebView object in the App Delegate, reference that one instance from any view and add it as a subview. Works like a charm. I also set its frame to the frame of a hidden UILabel in the view so I can use all of the Xib resizing. – Peter B. Kramer Oct 20 '20 at 01:24

score 1 · Answer 8 · answered Jun 19 '18 at 05:48

Mine was different again. I was setting the user-agent like so:

    NSString *jScript = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width'); document.getElementsByTagName('head')[0].appendChild(meta);";
    WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:jScript injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];

This was causing something on the web page to freak out and leak memory. Not sure why but removing this sorted the issue for me.

Removing JavaScript injection fixed the issue for me.... but now I need to find a workaround because i need the JS — Aaron, Jan 26 '19 at 01:25

Juanmi · Answer 9 · 2019-04-26T18:34:06.660

1

On OS X, it's necessary to make sure Sandbox capabilities are set-up properly in order to use WKWebView.

This link made this clear to me: https://forums.developer.apple.com/thread/92265

Sharing hoping that it will help someone.

Select the Project File in the Navigator, select Capabilities, then make sure that:
* App Sandbox is OFF,
OR
* App Sandbox is ON AND Outgoing Connections (Client) is checked.

edited Apr 26 '19 at 18:34

answered Apr 26 '19 at 16:56

Juanmi

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Include the actual answer instead of just linking to it. – RiddleMeThis Apr 26 '19 at 17:22

score 1 · Answer 10 · answered May 31 '19 at 14:12

1

Just for others reference, I seemed to have this issue too if I tried to load a URL that had whitespace at the end (was being pulled from user input).

answered May 31 '19 at 14:12

Dom Barnes

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score 1 · Answer 11 · answered Apr 02 '20 at 20:34

1

Deleting/commenting

- (void)viewWillAppear:(BOOL)animated {[super viewWillAppear:YES];}

function solved the problem for me.

XCode (11.3.1)

answered Apr 02 '20 at 20:34

sag

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score 1 · Answer 12 · answered Oct 09 '21 at 08:49

1

I tried almost everything, my solution was simple, updating MacOS to the latest version, and also Xcode to the latest version, that way the error was gone, white blank screen was not happening anymore.

answered Oct 09 '21 at 08:49

miloth

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score 1 · Answer 13 · answered Dec 14 '21 at 09:58

1

Just check your URL that you are passing to load request, I was receiving same error when I came to this page, later checked that I was getting URl starting from "www" Later I added "https://" , it works for me

answered Dec 14 '21 at 09:58

deepOcean

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score 0 · Answer 14 · edited Mar 27 '19 at 16:22

0

Perhaps the below method could be the cause if you've set it to

func webView(_ webView: WebView!,decidePolicyForNavigationAction actionInformation: [AnyHashable : Any]!, request: URLRequest!, frame: WebFrame!, decisionListener listener: WebPolicyDecisionListener!)

ends with

decisionHandler(.cancel)

for the default navigationAction.request.url

Hope it works!

edited Mar 27 '19 at 16:22

ohglstr

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answered Feb 01 '19 at 13:53

Pradheep Narendran P

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com.apple.WebKit.WebContent drops 113 error: Could not find specified service

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