in your browser. After you get asked for your username and password there you need to be redirected to a page stating something like:
This is the WebDAV interface. It can only be accessed by WebDAV clients such as the ownCloud desktop sync client.
If that is working it might be possible that your *DAV interface / setup is not working completely / fully. For that we have a FAQ thread available (especially the litmus part there can help you to check your environment):
I'm very afraid! All this mess was generates by The wrong password! Infact, Davdroid does not communicate if the credentials are incorrect but only the above generic message.
Everything is resolved now, sorry If I bothered you!
The detection process is quite complicated, and it's not possible to tell whether the single steps return 401 for a good reason (for instance, because well-known URLs are not configured or because the user-given URL returns 401, but the automatically detected ones work) or because of the wrong password. We have thought over the detection process and how to show errors many times, and I hope that it's quite a good solution now. When you click on "View logs", you see every request + what the server returns, so all the 401 messages from the server should be a good hint that the password is wrong. If you have specific ideas on how to improve that, please let us know.