Logins failing

Our environment

3.7 on a linux machine, connecting to a windows domain.

Been working brilliantly for many years now, little things here with memory and other items but nothing that was not solved mostly with a reboot.

Today however no new logins are being accepted. My admin account can not login to administer anything.

We are in the midst of putting in and removing domain controllers. Though we have not removed the last old one yet. First one was removed a month ago.

I am betting that i have a link to the last DC in the config for open fire, but i dont know where or how to access it. It should still be responding, but its not for wome reason, and we would need to change it anyway.

My linux guy has left us long ago, and i know enough to be dangerous to myself lol

i was looking thru the linux admin guide for set up but its all greek to me.

can anyone point me in the right direction.