I just purchased DAVdroid from the Google Play Store: it is version 184.108.40.206-gplay
I store my calendar on my personal server. This works fine with Apple’s Calendar.app and Mozilla’s Thunderbird (Lightning). I don’t use CardDAV, only CalDAV.
When I try to setup DAVdroid, I choose “Login with URL and user name”. I set the base URL to the same URL used by Calendar.app (Thunderbird doesn’t seem to support calendar-home-set, so I have to add the calendar name to the URL used by Thunderbird).
I use the same username and password that work fine with Calendar.app and Thunderbird.
DAVdroid then complains that it can’t find any CalDAV configuration on my server. I have pasted the debug logs here: https://paste.fedoraproject.org/paste/kb9R3FwUL6JnR~MYCytbqA
From the logs, it seems to be trying the URL that I provide but failing with a 401 Unauthorized error. I am definitely providing the same username and password that work in my other CalDAV clients (i.e. Calendar.app and Thunderbird) and which also work if I open that URL in Firefox.
Any idea why DAVdroid cannot authenticate? Is there any more information I can provide that would help you to debug this?
Thank you for your help.