You did not say if you configured the NextCloud in any way for an AD on Win2019…
Normally, AD integration will work, AFAIK only if AD is the same NethServer. Otherwise you will need to “tune” the settings to match your AD.
Another caveat is the fact that PHP and Java (Nextcloud uses PHP) web applications are fussy about TLS/SSL issues. NethServer’s AD can use a valid LE certificate, but what about Windows?
This is often an unexpected dealbreaker!
Please check howto:nextcloud [NethServer Wiki] , maybe the database isn’t running?
As the internal Nextcloud admin can’t login, does it work with an AD user?
Maybe it helps to reconfigure NC:
signal-event nethserver-nextcloud-update
Please check the Nextcloud log for more info about the error.
I think I got 99% to work, I just logged in with the nextcloud-admin befor I joined the Windows Domain.
I am now able to use Nextcloud Talk with the AD-Users, there is just one error when I try to bind an external Storage. Looks like the ugly error befor:
No extra step is needed to get the AD-User under Nextcloud. Just join the Nethserver to the Windows domain and you should be able to login with AD-User credentials.