IOS 12 Crash on launch, exactly after splash screen

[ekkescorner]

@Dimitar.Negrevski just tried to reproduce with my QtQuickControls2 App (Qt 5.10.1) on iOS 12, but got no crash.

[Dimitar.Negrevski]

@ekkescorner With Qt5.9.4 with qt examples it is not 100% reproducible on all devices. But we have one device on which it is 100% reproducible with all applications, but we still can't understand what exactly is causing all qt apps to crash on this iPhone 7(ios 12). I compare most of the device settings with other device on which it is not reproducible with examples, and everything looks same. In few days I will test it with Qt 5.10 or Qt 5.11 too, and I will write what's the result on this iPhone with this Qt versions.

[ekkescorner]

@Dimitar.Negrevski https://bugreports.qt.io/browse/QTBUG-70683 seems to be a similar issue

[Dimitar.Negrevski]

@ekkescorner Yep, it looks similar, it will be interesting if they find another workaround.

[maitai_vw]

I have I think the same problem (Widget based application crashing for some users after upgrading to iOS 12)
From the bug reports it is not clear to me if there is a workaround?

[Dimitar.Negrevski]

@maitai_vw For our QML application, adding a title to our QML Window fix the crash.

[maitai_vw]

@Dimitar.Negrevski Thanks for your reply
My app is widget based. Adding a title to mainwindow passed the crash, but that is not enough. Uses cannot access any menu anymore (i.e. when taping on an action it crashes). Investigation is underway but difficult since I do not have an iOS device compatible with iOS 12.

[ekkescorner]

@maitai_vw said in IOS 12 Crash on launch, exactly after splash screen:

... I do not have an iOS device compatible with iOS 12.

have you tried with Simulator ?

[Dimitar.Negrevski]

@maitai_vw Are you sure that menu crash is related to IOS 12, cause with our QML App, we don't have any problems with Menu.

[maitai_vw]

Still searching on that one.
I have 2 users concerned, on iPhone 6S both. Many others do not have the problem
I do not have a 6S to test with, even worst no device iOS 12 compatible.
Only thing I can tell is that I get this crash report in XCode from appstore

UIAccessibility: _axuiElementForNotificationData

and nothing more.

Users swear they didn't set any accessibility stuff. Only common point is that they are both located in Swiss, lol.

[maitai_vw]

Just to add that I have now switch from Qt 11.1.2 to 5.9.7, same pb for these users.

[maitai_vw]

Finally it appears that users were, well, lying. They did have some accessibility options on, namely "speak screen" and another one. Once they finally removed it's all OK
To summarize:
I had the crash you reported, and I added a title to mainwindow (my app is widget-based, not qml)
That fixed the crash. But still there is a crash later if user is calling a qaction (I guess it's trying to speak the qaction.).
Is there a setting in plist or something to override to avoid that?

[maitai_vw]

And finally the problem disappeared with iOS 12.1, without doing anything else. Even the trick with the title is not necessary anymore.

[Dimitar.Negrevski]

Yep, it seems that with IOS 12.1 everything is fine, without any workaround. How can I mark issue as resolved?

[SGaist]

Thanks for the confirmation !

You can use the "Topic Tools" button for that :)