Sorry for delay. I reported this as bug against Horde:
ownCloud 8.2: Calendar syncs ok, tasks have stopped after DavDroid update
I tried uninstalling the DavDroid app and reinstalling it – still getting errors found here: https://paste.fedoraproject.org/382927/65722921/
Anyone know how I can troubleshoot the problem with syncing tasks to OpenTasks? I keep getting “Server error while listing remote entries” notifications.
This is a server error. Your server returns a 200 OK response instead of a 207 Multi-Status response on a
at.bitfire.dav4android.exception.InvalidDavResponseException: Expected 207 Multi-Status, got 200 OK
You will have to fix it on your server.