Core Apps » Orbot

Orbot version: 13.0.4a (from latest apk on your website, not F-Droid)
device: Fairphone (v1.1 "Caju", built-in superuser management, see https://fairphone.zendesk.com/hc/en-us/search?query=superuser)

Here are the steps I (think I) went to make this problem appear:

1. install Orbot from https://guardianproject.info/releases/orbot-latest.apk
2. configure transparent proxying & confirm superuser prompt forever => Orbot works fine
3. install alternative superuser app; I used https://f-droid.org/repository/browse/?fdid=com.koushikdutta.superuser => Orbot still works fine
4. uninstall alternative SU app => Orbot starts to report the above error & in the "Permissions"-wizard, clicking "Request Superuser Access" leads directly to the next screen ("Transparent Proxying"), without SU confirmation prompt by Fairphone OS; Orbot also doesn't appear in the OS's SU list anymore.
5. exit Orbot app via its menu => launches the wizard again; app has to be killed to exit
6. installing alternative superuser app again fixes the problem, so this could be a bug in Fairphone's OS (not taking over SU management after alternative app is uninstalled), or in F-Droid or the alternative SU app (not handing over SU management to OS again)