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We have a client that runs our app in guided access mode.

The app runs flawlessly for 2 days consecutively, but after that, the iPad suddenly lags, sometimes crashes and reopens, and after that, the screen goes black. If they press the home button the screen goes active with the app still running.

If they close the app, reopen it and restart guided access mode the same thing will happen much sooner. A complete reboot is required, and after that, the app will run flawlessly again for 2 days

We've done extensive testing on our side, but are unable to reproduce the issue. Intensive usage of the app doesn't seem to trigger the issue sooner than 2 days. However, if you use the app too little or not at all and it'll keep running fine.

Does anyone know what might be happening here and how we can prevent it? To my knowledge, an app shouldn't be able to break the Kiosk mode and let the device go to standby.

Some general information:

  • The app was built with React Native
  • We use the Lottie library for animations and standard js timers to trigger certain events
  • Turning off some of the animations seems to postpone the 'crash'
  • The iPads are placed on a stand and use a nonstandard charging cable
  • I've monitored the app and was unable to find a memory leak

I found an entry in the device logs that seems to happen alongside the issue, but I was unable to determine if it's a cause or a result of the issue. 

Date/Time:       2018-03-18 11:51:21.622654 +0100
OS Version:      iPhone OS 11.2.6 (Build 15D100)
Architecture:    arm64
Report Version:  19

Command:         AppName
Path:            /private/var/containers/Bundle/Application/2CBF6CD5-361E-41B3-8BFD-B80F73360F49/AppName.app/AppName
Version:         1.17 (12)
Beta Identifier: FB6349BF-3B73-4519-8FE2-852CC4FFC82B
Parent:          launchd [1]
PID:             187

Event:           wakeups
Wakeups:         45001 wakeups over the last 299 seconds (150 wakeups per second average), exceeding limit of 150 wakeups per second over 300 seconds
Action taken:    none
Duration:        299.27s
Steps:           119

Hardware model:  iPad6,11
Active cpus:     2


Powerstats for:  AppName [187]
UUID:            3A4499E3-13C5-361C-B591-1429A6E9F52A
Start time:      2018-03-18 11:54:52 +0100
End time:        2018-03-18 11:56:19 +0100
Microstackshots: 119 samples (100%)
Primary state:   89 samples Frontmost App, User mode, Effective Thread QoS User Interactive, Requested Thread QoS User Interactive, Override Thread QoS Unspecified
User Activity:   0 samples Idle, 119 samples Active
Power Source:    0 samples on Battery, 119 samples on AC
Kiran Sarvaiya
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Dirk de Boer
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    We have been seeing the same issue while in Guided Access Mode – but only on some devices and sometimes. We can't reliably reproduce it and not all customers are experiencing it. Did you find a solution? Apple has been unresponsive to our bug report. Our app was not built with React Native, FYI. It's plain Objective-C. – davidcann Apr 06 '18 at 01:59
  • I'm afraid we still haven't found a definite solution. We did however have contact with Apple and they state the application shouldn't be able to mess with the Guided Access Mode settings, and thus it is a bug in iOS. We made some changes to our application, disabling numerous animations. According to our client the app has been working much better ever since (no more crashes). This means it could be something in the animation frameworks – Dirk de Boer Apr 13 '18 at 09:19
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    For what it's worth, this issue disappeared completely in the production release of iOS 11.3. We experienced the issue in at least some of the iOS 11.3 beta releases. We made no changes to our app. – davidcann May 09 '18 at 02:56
  • @davidcann Are you still seeing this issue, I have been seeing it with some devices on 11.4+ but only some devices and the timing seems random. – tagy22 Aug 10 '18 at 11:14
  • We still see this issue, but much less frequent with the update to 11.3. We also notice that the kiosk mode iPads become slower overtime. A full reboot is required to fix this problem, simply closing the app does not work. This seems somehow related to the issue. – Dirk de Boer Aug 14 '18 at 09:16
  • @tagy22 We haven't seen it or heard from customers about it since at least iOS 11.3.1, including 11.4.x. – davidcann Aug 28 '18 at 22:24
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    Just an update – we're seeing this behavior yet again in iOS 12 Public Beta 10, except it's happening after less than an hour. We don't know in which beta of iOS 12 that it started happening again. – davidcann Sep 07 '18 at 19:22
  • Thanks for the heads up. We'll watch out with updating to iOS 12 when it's released – Dirk de Boer Sep 08 '18 at 22:59
  • All, our organization is seeing this now with the rollout of iOS 12. Happens to (some) of our kiosks after a matter of minutes. – WakeDemons3 Oct 18 '18 at 16:14
  • Is there any solution for this?? – Nicks Oct 20 '18 at 11:35
  • @ sumit, no apparently is a widespread bug. I read on a forum that as of oct 25, Apple stated it was a "Priority 1" issue... – dangel Oct 29 '18 at 15:48
  • I can confirm this is still happening on iOS 12.1.1 beta – Steven Mark Ford Nov 09 '18 at 00:41

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