Cwa-app-ios: version 1.2.0 crash on startup with deactivated background app refresh

[Flamingo07]

Avoid duplicates

• [x] Bug is not mentioned in the FAQ
• [x] Bug is not already reported in another issue

Describe the bug

app closes on boot, I just updated

Expected behaviour

Steps to reproduce the issue

Technical details

• iOS Version: 13.6
• Device: iPhone XS (A2097)

Possible Fix

Enable Background App Refresh (Hintergrundaktualisierung)
iOS Settings -> "General" -> "Background App Refresh"

Additional context

---

Internal Tracking ID: EXPOSUREAPP-2193

[Ein-Tim]

Can't confirm this behavior on my iPhone XR with iOS 13.6
Did you restart your phone? @Flamingo07

[Flamingo07]

are you on 1.2.0? i have a XS on ios13.6, already restarted the phone. is the update still available? it doesn't show up in update history on the App Store

[Ein-Tim]

Yes, I'm on 1.2.0 (8) and the update is shown in the Update history in the App store.

[Flamingo07]

hm very strange but now the update is shown for me as well, again. can't update though, ill try to reinstall the app.

[Flamingo07]

that fixed it but "Ermittlungszeitraum" has been reset

[drocx]

I have the same problem.
The app crashed at startup after update to version 1.2.0

iOS 13.6
iPhone Xs
German Language

[daimpi]

@Flamingo07 maybe leave the issue open for a bit… other users might also have this problem :).

Btw: when you re-installed the App, the number of "active days" was reset to 0, right?

[rainerhgit]

Same issue here on iPhone XS and iPhone 11pro with iOS 13.6:
App crashes after update to Version 1.2.0
Reinstalled the app. Then it works but day count now zero.

[tcfos]

iPhone X, iOS 13.6, updated CWA to 1.2.0 (8) w/out any issues
iPhone SE (1st gen), iOS 13.5, updated CWA to 1.2.0 (8) w/out any issues

[gotcha9999]

Crash with iPhone 8, 13.6. After reinstalling the app is working but all previous data is lost.

[daimpi]

@gotcha9999 The data is not lost, only the day counter is reset to 0. But that's only a visual aspect, on the functional side everything should be fine :)

[tens0rfl0w]

iOS 14 Dev Beta 4, can confirm crash on startup.

Happens if I open the app, force quit it, and then open it up again immediately. This does not happen if I wait some seconds between the two starts.

Update
Bugs self regulated itself, after some time the crash is not reproducible.

[Engholm]

Same here. iOS 13.6 / iPhone XS. Crash on startup. Reboot doesn't help.

Workaround that works for me: iOS Settings -> "General" -> "Background App Refresh" was set "Off". I switched it on, allowd CWA to refresh in the background and started the App. No crash at this time. After this I switched off Background App Refresh again. The CWA started without trouble and asked for the manually logging oder switch to settings for the automated background refresh.

I guess it could have something to do with checking the background refresh service?

[drocx]

@Engholm @rainerhgit I can confirm that enabling "background app refresh" fixed the bug.

[thomasaugsten]

Can somebody with a crashed app please upload the crash report if there is any crash report available

Settings->data privacy -> analysis (end of the list) -> analysis data and search for a file starting with ENA

[tobihagemann]

{"app_name":"ENA","timestamp":"2020-08-12 07:45:55.00 +0200","app_version":"1.2.0","slice_uuid":"xxxxxxx","adam_id":xxxx,"build_version":"8","bundleID":"de.rki.coronawarnapp","share_with_app_devs":1,"is_first_party":0,"bug_type":"109","os_version":"iPhone OS 13.6 (17G68)","incident_id":"8AB2F82D-855A-4959-9CE7-96B78549A8F4","name":"ENA"}
Incident Identifier: 8AB2F82D-855A-4959-9CE7-96B78549A8F4
CrashReporter Key:   b9a0db9a75e38b22cf1cb1e9d8260028eb5f5968
Hardware Model:      iPhone10,6
Process:             ENA [1566]

EDIT: shorten for readability of the issue thanks again for providing

[thomasaugsten]

Thanks for your help we will publish a hotfix soon.

[daimpi]

Is this crash coming from the new check for "Background App Refresh" which is performed on startup? : https://twitter.com/henningtillmann/status/1293442164400238592

That would explain why ppl who had problems with "Background App Refresh" already before 1.2.0 are now also having this issue: https://twitter.com/kiwein/status/1293500709544042498

BTW: If anyone has any idea how to fix the problem of the greyed out "Background App Refresh" slider for the person from the latter tweet, feel free to chime in :)

[toto]

@daimpi Not 100% sure, but it could be disabled via MDM when roaming. According to the Jamfnow FAQ here there is a restriction _Disable Background Data Usage When Roaming_ for iOS.

[PalminX]

@toto The issue is not that background refresh is disabled for CWA, but is enabled and cannot be changed.

[thomasaugsten]

We released v1.2.1 with a fix for the crash. Thanks for your help and patience.
https://github.com/corona-warn-app/cwa-app-ios/releases/tag/v1.2.1

Greyed out Background Refresh has multiple reasons. I know the following:
Background App Refresh for the OS is deactivated
Low Power Mode
Background App Refresh disabled by a Enterprise profile MDM

[PalminX]

Greyed out Background Refresh has multiple reasons. I know the following:
Background App Refresh for the OS is deactivated
Low Power Mode
Background App Refresh disabled by a Enterprise profile MDM

In this case, the user who reported this on Twitter checked all of the options that you mention. The background refresh was set to "on", but the UI setting was disabled. The first two possibilities would show the setting set to "off" with a disabled UI. Very strange still.

[PalminX]

We released v1.2.1 with a fix for the crash. Thanks for your help and patience.

Is this released/submitted to the AppStore already? (Edit: found the Git tag)

[thomasaugsten]

@PalminX I can reproduce a gray ON Button
Activate background for the app. Disable Einstellungen->Hintergrundaktualisierung-> Erster Punkt Aus
Einstellungen-> Corona-Warn-App you see gray ON Button
I added the release notes in the comment

[sin-azucar]

Update 1.2.1 is available now on the App Store. That was a quick fix. 🙏

[daimpi]

@thomasaugsten the issue with they grayed out "on" button was indeed fixed by turning the main setting for "Background App refresh" on again and everything worked fine from there on: https://twitter.com/_Palmin_/status/1293553304014852096 😄

[thomasaugsten]

I happy to help here. Thanks a lot for your Twitter work this is very important and helps a lot of people.

I will close the issue here because the issue is solved.