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#129 SEB crashes and gets stuck on "Single app mode no allowed" error
Issue has occurred on 140 identical iPad Airs 8th Gen Model A2270 running iOS 14.4
Managed via Apple School manager and VMWare AirWatch MDM.
SEB installed via MDM deployment, config file for SEB manually downloaded and opened in SEB from URL link via Safari.
Config file set to every default setting, except URL start page, URL exit link, manual quit password, and file admin password. (File attached)
MDM AirWatch profile pushed to iPads specifically allows SEB (Application Bundle ID: org.safeexambroswer.ios.seb) to go into Single App Mode.
When manually adding the SEB config file to the iPads (we currently have no means to host the file anywhere to access within the SEB app) one of two things happens:
1) The app will open and show the error message: "Single App Mode/Guided Access Not Allowed. Current settings require that Guided Access or an MDM/Apple Configurator invoked Single App Mode if first switched off before the exam can be started. [Cancel] [Retry]"
Pressing [Retry] will just make the same error message appear, pressing [Cancel] will get to the "Exam Session Finished" message.
Despite the message saying "you can exit SEB using the Home button/indicator", the app cannot be minimized or closed.
Pressing the "[Start another Exam]" button at the bottom seems to crash the entire app, but then immediately reopen it and bring up the "Single App Mode not allowed" error.
This loop will continue with no way of getting out.
At this point, if I hold the Power and Home button to reboot the iPad it will restart, SEB will automatically open, and then show the same error message or the app will lose the config file and it will have to be redownloaded again.
At this point, pressing the [Cancel] button on the error message will cause the app to pause for a moment, then go to the correct URL given in the config file, and seemingly be working.
I can then use the app as normal, quitting out via the exit URL or quit button.
2) The app will load the config file correctly and go to the start URL.
I am able to use the app correctly, quitting SEB with the exit URL or quit button.
However, when doing so, the "Exam has finished" message will pop up and immediately the app will crash then reopen to the "Single App Mode not allowed" error.
At this point the app will behave exactly as in the 1) section.
In either instance, once the reboot has been performed and the app starts working correctly it then continues to work correctly for a while. However twice in succession I have come back in to work and tested the same batch of 50 iPads and on 47 the issue occurred again the same way when launching the SEB app with the config file still applied.
We have seen via the SEB twitter feed that there is a beta test that might fix the issue, however we are needing to use these iPads and App for a National Exam starting on the 29th March. So need to have this issue ironed out A.S.A.P by the end of this week so we can sign off the devices as ready to the examining body. (They are the ones who advised to use SEB but provided no further guidance or support, I have had to learn how to use and deploy this software by myself only using the online documentation in a very short amount of time)
Is there a solution to this issue? As it is causing no end of stress that the app seemingly locks into an error message loop when left off overnight. The above fix is not permanent and I cannot find a stable solution to make them work.
removing the devices from the MDM is not an option.
I have recorded the issue happening here:
https://drive.google.com/file/d/14DVUOD6O9beLEkqq6bZiEQ7AzGekwXje/view?usp=sharing
Discussion
In addition, after a colleague pointed me to the Beta version of the App available via TestFlight, the issue is exactly the same on 3 devices I tested it on.
As you already tested the beta version without success, my best guess is that this is the issue related to a bug in the iOS UIWebView browser engine, when WebContentFilter is enabled (which usually is the case with MDM managed devices in schools), see this discussion (at the bottom): https://sourceforge.net/p/seb/support-requests/122/
Are you using WebContentFilter? Could you disable it and test again, if the issue still happens?
If it still happens, I would need crash logs and SEB log files to try to analyze the issue further, see that other thread for where to find those logs.
If it doesn't happen with WebContentFilter disabled, then either you can do that during the exam or try to add all domain (including subdomains) which are used in your exam system as allowed domains in WebContentFilter. That might prevent these crashes in SEB from happening (although it might not be easy to determin all domains which are used in your system, and it's not guaranteed that the issue doesn't happen when those domains are allowed, but WebContentFilter is still activated).
I'm working on integrating the newer web browser engine WKWebView, but that won't be finalized until Friday. We have limited developer resources to develop and maintain this freeware software, and recently we have to find workarounds for many iOS and macOS bugs. Your organization/examining body could support the development of SEB by becoming a contributor to the SEB Alliance https://safeexambrowser.org/alliance/
I cannot seem to get to the option to "Send Logs to SEB Developers", as you stated in the other reply, I can't do so while I've loaded the config file.
If I try to quit the exam using the button in the bottom right, after putting in the quit password I am just met with the "Exam Session Finished" message with no control except starting the exam again or closing out of the app.
When I check the options in Settings > SEB, neither of them allow me to access that "About SEB" page when opening the App. Even if I strip out the config I am only met with the "Options to start an exam..." message with no access to an "About SEB" menu.
I have also had a look under Settings > Privacy > Analytics & Improvements > Analytics Data.
But there is nothing that starts with "SEB."
The best I could find is a "log-sessions-[todays date and time].session" which mentions "org.safeexambroswer..." in the text. (Attached to this reply)
We don't use any WebContentFilter on the iPads, outside of the SEB app the iPad has fully unrestricted use. No white/black listing of any URLS. We have only been given the one URL to add as the start URL and then a second exit URL set within the SEB config file. No further restrictions were required.
Last edit: Nic Lewis 2021-03-17
WebContentFilter is used by parental controls, but it doesn't look like you're a K12 school...
Best is to use the 2.1.50 beta version. There you can initiate sending the logs in the iOS Settings app in the SEB section (and also I improved logging to better be able to analyze such problems).
You can also try to remove the MDM setting in your MDM AirWatch profile pushed to iPads which specifically allows SEB (Application Bundle ID: org.safeexambroswer.ios.seb) to go into Single App Mode. Then SEB will use the BYOD single app mode called AAC or Assessment Mode (instead of the managed single app mode ASAM). One difference is, that with AAC SEB isn't restarted by the system after restarting the device.
We did try removing the MDM controlled single app restrictions, I reset one of the iPads earlier to have nothing but the MDM assignment control, no applied profiles or apps. Manually downloading SEB from App Store and trying from scratch. Same error result, just that the app asked to confirm locking into Single App Mode before a "No Kiosk Mode allowed" error message appeared, which after a reboot became the "No Single App mode allowed" error
Even using the Beta, the exact same issue occurred.
As far as I can tell, reading Apple's TestFlight description, you can only have 30 devices with the Beta App installed, which doesn't seem viable when we have 140 iPads in use for this exam. Additionally we don't assign iCloud/iTunes accounts to the iPads as all app deployment is managed by the MDM, which prevents us setting up the TestFlight app on each individual iPad.
I still hope the newer web browser engine will solve the crashes. If I can't reproduce the issue, I can't fix it. It must be connected to MDM enrolled devices or maybe even that VMWare AirWatch MDM, as I don't observe any similar crashes on any of my test devices. Even on the two devices which are enrolled in the Xcode Server Profile Manager MDM and one in Jamf Pro SEB doesn't crash and the single app mode works. SEB was installed on over 153'000 devices worldwide, and you're just the third person reporting similar issues with the single app mode, and in all cases MDM enrolled iPads are affected. Also I'm getting a constantly low number of crash logs from users which activated "Share iPad Analytics & Share With App Developers" (please do that on your testing devices). So I'm a bit confused what could cause this issue.
Please try again to send me the SEB log files using the option in the Settings app / SEB as shown in the attached screenshot, when you have the beta version installed.
If I can fix the issue, I could quickly update the App Store version, as the beta version seems to be stable in all other test cases.
Btw. the Initiate Sending Logs feature in the beta version still has a flaw, it doesn't send the logs after starting SEB freshly, but if you start it, go back to the home screen and return to SEB, it should work.
I guess crash logs in Settings > Privacy > Analytics & Improvements > Analytics Data are only generated on devices activated for development in Xcode. Unless you haven't had "Share iPad Analytics & Share With App Developers" activated, which might be the other reason (but it wasn't the sole reason in a case in the other thread).