DAVdroid is asking for permission to sync tasks with OpenTasks. When I hit the button, nothing happens. I already tried to reinstall both apps (first OpenTasks, then DAVdroid), but nothing helps. Granting access to my system calendars and contacts is working fine. Both apps been running completely fine until Friday (10/14/2016). It is possible that my phone did an automated update of one of the apps in the background. I am not aware of this. I am using a Sony Xperia Z3 (D6603) with Android 6.0.1.
Please help me ASAP.