I have some problems using webdav with nextcloud 12. Webdav is working without problems with the following clients:
macOS owncloud client (version 2.3.1)
iOS next cloud client (version 2.17.3)
windows 10
transmit (version 4.4.12) and a few other clients.
But I am not able to use webdav with
macOS finder (macOS 10.12.5)
transmit for iOS (version 1.3.6)
or
forklift for macOS (version 3.0.5)
These three clients shows a “HTTP Request failed: (401) unauthorized” failure. I double checked the configuration, the log files of next cloud or nginx, but I did not find any hint to solve the problem. With next cloud 11 everything works fine.
Hey i have the same problem with archlinux and the gnome callendar, i can sync the cloud with the nextcloud client on my smartphone and my archlinux and on my smartphone syncing the calendar works, but on my laptop i get a big nope, adding the /remote.php/dav/ after the server name as the callendar suggests, it cannot find the WebDav endpoint, maybe for you it works by adding /remote.php/dav/principals/users/USERNAME/ after the server?