Serious issues have been reported with Survey Solutions version 21.05.6
(see e.g. here: Interviewer app hangs and crashes (Again))
Users that have not updated yet to version 21.05.6 are recommended not to update to it and remain on the previous stable version. Users that have already updated and experience the issues as shown in the post cited above, please await for the patch, our team is working on it.
Any inconvenience regarding this issue is regretted.
Version 21.05.7 doesn’t completely fix the issue. Some interviewers are reporting that the app is not opening even after the update. While the app works for others. We are not able to point any apparent difference in the two from our end.
Interviewers with the same tablets and same update pattern, have reported different outcome. App works for one and not for other.
Uninstalling and reinstalling works, but not without data loss. We were able to get those interviewers who didn’t have any data on the tablets up and running by simply uninstalling and reinstalling the app.
These issues were fixed and we recommending to update Survey Solutions to the latest version.