Console shows AutoLayout Engine Warning while loading UIWebView and Crashes the app sometimes

Question

Summary: While trying to load the URL/HTML string on UIWebView console shows warning like "This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes." and crashes the app at some point.

Steps to Reproduce:

Load URL/HTML String on UIWebView.
Console will show the AutoLayout engine warning.
App Crashed some times(Uncaught exception: Only run on the main thread!).

Expected Results: App should not show any warning while loading UIWebView and should not crash the app due to that warning.

Actual Results: This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes.

    Stack:(
        0   CoreFoundation                      0x0000000188e35998 <redacted> + 148
        1   libobjc.A.dylib                     0x00000001884304bc objc_exception_throw + 56
        2   CoreFoundation                      0x0000000188e358c8 <redacted> + 0
        3   Foundation                          0x00000001899a3da0 <redacted> + 192
        4   Foundation                          0x00000001899a3b00 <redacted> + 76
        5   Foundation                          0x0000000189808548 <redacted> + 108
        6   Foundation                          0x00000001899a2788 <redacted> + 104
        7   UIKit                               0x000000018ebbc76c <redacted> + 1464
        8   QuartzCore                          0x000000018c0e0d6c <redacted> + 148
        9   QuartzCore                          0x000000018c0d5aac <redacted> + 292
        10  QuartzCore                          0x000000018c0d596c <redacted> + 32
        11  QuartzCore                          0x000000018c0554fc <redacted> + 252
        12  QuartzCore                          0x000000018c07c7c4 <redacted> + 512
        13 

 QuartzCor

iOS Version: iOS 10 beta 1

Xcode version: Xcode 8 beta

This issue has been resolved in iOS 10 beta2.

Thanks!

Could you show the code? – Mtoklitz113 Jul 04 '16 at 14:47 — Mtoklitz113, Jul 04 '16 at 14:47
And do indicate where it crashes as well. – Mtoklitz113 Jul 04 '16 at 14:48 — Mtoklitz113, Jul 04 '16 at 14:48
This issue has been resolved in iOS 10 beta2. Thanks! – Natarajan Jul 18 '16 at 07:14 — Natarajan, Jul 18 '16 at 07:14
http://stackoverflow.com/a/28321213/6521116 – LF00 May 17 '17 at 07:54 — LF00, May 17 '17 at 07:54

score 1 · Accepted Answer · answered Jul 18 '16 at 07:17

1

This issue was happening in iOS 10 beta1 and I filed an issue in Apple Bug report with sample project. Now the issue has been resolved in iOS 10 beta 2.

Thanks!

answered Jul 18 '16 at 07:17

Natarajan

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Console shows AutoLayout Engine Warning while loading UIWebView and Crashes the app sometimes

1 Answers1