I've got a setup where I am trying to rescue a broken AD. We can no longer authenticate on the Workgroup manager, with passwords being rejected all the time - even though it is correct. I can connect using the workgroup manager on another server and I get the user list as expected, but when I click the padlock to make changes, I get the following screen:

The problem is, I know the password is correct, I just used it to connect to the server in the first place.

I can log into the server using the local admin, and services such as AFP, VPN and SMB continue to serve users. I have about 300 or so users on this server, and I would very much like to avoid having a rebuild.

As there is much configuration that has been done without my knowledge (it's a client machine), I'd like to attempt to fix it, and then create another server and migration OD off this broken machine, then decommission it "gently". Ultimately this would mean no disruption of services.

What I'd like it some tips as to how to fix the problem with authenticating to make changes in the work group manager, and maintenance on open directory in general.

Thanks