ReadyNAS NV+ v2 Error in prep join domain

[nushadir]

I have recently bought ReadyNAS NV+ v2. Firmware RAIDiator 3.5.7
I can't join this device to domain, my efforts ends with "Security failed Error in prep join domain"
Network connectivity between DC and NAS - check
DHCP leasing - check
Name resolving - check

NAS ip 192.168.100.13
Access type - Active directory
NetBIOS Domain Name - domain1
FQDN - nas.domain1.ru
Administrator Name - domain1\admin
Administrator Password - password
Directory service adress - 192.168.100.1 (DC)

But all of efforts results with this - after pressing "Apply" - "Security failed Error in prep join domain"
Help anyone, all suggestions welcome
Thanks in advance

[nushadir]

Don't think so. I believe that Directory service address is the address of domain controller. Am I right?

[dragonsat]

I have exactly the same issue.

Everything is set as required. The nas and DC are sat side by side on my desk.

Other computers and a buffalo terrastation are able to join without issues.

Tried different versions of the username eg user or DOMAIN\user or even user@domain none work.

Always the same response.
Latest firmware loaded.

[Cartref]

I am having the same problem.

I have 6 other earlier models of the NV+ and NV. They all had different a different screen (of course the font end has changed) but this version is stumping me and I have seen no specific instructions to use

[kdorsey]

*REFRESH*
This post comes up first in searches, so t would be great to have a comprehensive solution posted here, too.

ReadyNAS NV+ v2
FW: 5.3.11
Host AD: Server 2012R2

Fields:
NetBIOS Domain name: ABC
DNS Realm Name (FQDN): abc.local
OU: /Users
Administrator name: DomainAdmin
Directory Server address: 192.168.1.100

What syntax problem do I have here? Since the readynasd.log states "prep_join_ads_domain: orgUnit exist, _check_ou_exist failed", my syntax for the OU must be wrong. I've tried leading slash, no slash,etc.