Windows 2019 server UAC

Question

Hi
I am having issues with DC connectivity/authorisation.

My topology is as follows:

Windows 2012r2 as AD/DC

Windows 2019 as a domain member computer (remote location, but integrated on LAN through dark fiber)

When I remote desktop onto the w2019 server, and log in as domain admin (which is something that I used to do on daily basis up to two weeks ago) I can do whatever I am supposed to do, but....

If I try to change the security options (add/remove user permissions for example) UAC prompts me for domain username/password.
After I type in the SAME PASSWORD that I used to log in this session as domain admin I get the response
"The following error occured while using the username and password you entered:
The username or password is incorrect"

Opening the SAME option as "Elevated" Domain user works fine, just NOT as domain admin.

DC is visible on the network (and, yes, I checked if the DC is primary DNS, all checkups say it is - ping the alias, pwrshell, ipconfig, etc...), I can even open shares from it (which local users can not) so I am stumped at the moment.

Any suggestions?

Thx

Answer 1

Sounds to me like this member server is somehow broken. You might try standing up a new one for testing to confirm.

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 2

Any errors in the event logs? If you need UAC on the server, have you tried to disabled it reboot and enable it again?