How does lansweeper decide which DC to look at for AD?
Lansweeper queries all DC's in the domain because a workstation only logs on to one of the DC's and this field isn't replicated to the other DC's by microsoft design
can we specify a DC for lansweeper to look at?
No, see previous question
Does Lansweeper use WMI to scan the DC holding AD?
No, Ldap is used
I will not be able to get the dcdiag command output
Replication problems and other active directory problems can be a big problem for Lansweeper contacting some dc's (and other programs)
a "dcdiag /e /q" should give no output on a fully working forest.
"The server is not operational" means that a domaincontroller is not active or not working.
If your clients log on to this one and lansweeper can't contact it for some reason then this is the cause of the problem.
I am trying to help resolve this problem, but when you get one reply a day, it's kinda hard to get things done.
24/7 support is not always possible considering the time difference.
Also please provide screenshots of your configuration as asked.
Since you are the only one affected by this problem so far I suggest to contact lansweeper@hemoco.com so we can organize a remote control session to your server.