Nextcloud 16 won't connect (No 'Authorization: Bearer' header found.)

I already posted this in the github issue tracker here: #2219. Tessus gave me the recommendation to crosspost this issue here, as it might find a lot more eyes…

When I try to setup Syncing with my own nextcloud instance from my Windows Client, the connection fails with the following Error:

Error. Please check that URL, username, password, etc. are correct and that the sync target is accessible. The reported error was:
PROPFIND : Username or password was incorrect, No 'Authorization: Bearer' header found. Either the client didn't send one, or the server is mis-configured (Exception Sabre\DAV\Exception\NotAuthenticated) (401): <?xml version="1.0" encoding="utf-8"?> <d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns"> <s:exception>Sabre\DAV\Exception\NotAuthenticated</s:exception> <s:message>Username or password was incorrect, No 'Authorization: Bearer' header found. Either the client didn't send one, or the server is mis-configured</s:message> </d:error> (Code 401)

The credentials come directly from my password manager that I also use for logins into the web interface of nextcloud, so there is no way they are wrong (I additionally tried to type it by hand, with no real success). The URL points to an existing directory on the cloud instance and I tripplechecked that one as well (https://cloud.atoav.com/remote.php/webdav/Joplin). My certificate is not self signed.

The specivity of the message leads me to believe this could be a bug (maybe due to changes how nextclouds wants WebDAV Clients to authenticate?). I have 2FA deactivated in my Nextcloud installation. Maybe someone knows ways how I could dig deeper into it?

Environment

Joplin version: 1.0.175 (Build 8c1d13b3)
Platform: Windows 10 Pro
OS specifcs: 10.0.18363 Build 18363 (x64)
Nextcloud Version: 16.0.5.

Steps To Reproduce

  1. Enter username, password and URL
  2. Click the Button “Check synchronisation configuration”
  3. After a few seconds the above-mentioned Error message shows up.

Logfile

There is nothing showing up in the logfile – in my judgment the message above should be enough

Just wanted to give a hint, that this issue has been resolved:

What I did was to use my own username and password, while in fact I should have created a device password for Joplin and used that one instead. That means I had to go to Settings → Personal: Security → Devices & Sessions and create a new App name and password there for Joplin.