WEBDAV Authentification fails opening a vault

I try to open a vault using a webdav connection. At the same moment the password box for the vault appears a warning comes up in red saying “Benutzername und/oder Passwort falsch”.
I can create a new vault using my webdav connection, but after that I cannot access the vault.

Which storage provider do you use?

we use a special Service provided by a government agency called BSCW Server.
In the FAQ list you’ll find some Information about the Server.