WebKit on iOS 12.4 does not load my content which loaded on 12.3

My iOS application has a window inside of which a WKWebView is displayed. Some testers are complaining that since updating to iOS12.4 they can no longer load the content. I cannot reproduce this problem in our engineering offices and I cannot go onsite to the testers.


The WKWebView loads a javascript resource (remotely) into 'about:blank' which opens a web application in an iframe.

The webview reports that it has finished loading (webView:didFinishNavigation:), however the view is empty.


the thing is... on iOS 12.3 this works fine...

and on on engineering (non-hardened) environment everything works fine.


on iOS12.4.x on an environement with strict security, the webkit view load command does nothing.

most importantly, it does not 'fail' in the sense of calling webView:didFailNavigation:withError:


I realize that there were quite a lot of changes to WebKit for the iOS 12.4 release... am I the only one seeing regression problems? Or have I been doing things wrongly all along?


I was hoping to be able to debug the javascript in the Safari debugger, however because the problem is a load problem, I cannot set a breakpoint...


I also see a lot of private features in the open source WKWebView code which are not accessible via iOS12... is there some secret sauce which I am missing?


Any tips appreciated, thanks in advance for your insights,


|K<


additional info: ATS flag NSAllowsArbitraryLoads set to 'true'

Replies

I was having the same issue with iOS 12.4 and the way I found to get it going was just to add a variable to the AppDelegate.swift file
var window: UIWindow?

I'm not really sure why but it fixed for me.
Thanks

Hi,
I have the same issue. Our internal webpage does not open on iOS 12.4.x devices.
Did you end up finding a way around it?