Prolem with domain join


last week i did the Update to 4.4.4 from 4.3.X and the update on my Qnap NAS to Firmware 4.3.4 1282. Since then i got the message “The NAS registration in DNS failed” one a day. Since yesterday i can’t brows or open the folder on the nas as a domain user.

To solve this i tried to join the domain again. But the join failed. As next step i tried to join a Windows 10 PC to the domain but Windows can’t connect, too.

The NAS don’t give any hints but the Windows message is “Der Domänencontroller erfüllt nicht die Versionsanforderungen für diesen Vorgang”.

What can i do to solve this problem.

Kind regards,