Nextcloud version (eg, 10.0.2): 11.0.1
Operating system and version (eg, Ubuntu 16.04): Debian GNU/Linux 8 (jessie)
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.10-10+deb8u7
PHP version (eg, 5.6): 5.6.30+dfsg-0+deb8u1
Is this the first time you’ve seen this error and can you replicate it?: Error occurs across different installed instances.
The issue you are facing:
I try to access accounts via WebDAV  via “map network drive” in Windows 10[/edit] but the file list is empty (connection, that is login, works fine - not with Windows but with Dolphin on KDE). This happens only with users with special characters in their names which are created locally in the Nextcloud instance and with users which are stored in LDAP and connected to via “LDAP user and group backend” (I use usernames like “email@example.com” there).
When I use a local user without special characters (especially: no blank in the name) or use the UUID of an LDAP-user for WebDAV connection I can connect and show my files.
Login via web works fine with the “special character names”.
The output of your Nextcloud log in Admin > Logging:
The output of your config.php file in
/path/to/nextcloud (make sure you remove any identifiable information!):