I had a Windows 2003 server as my primary domain controller with all the FSMO roles. Three months ago, I purchased a new server with Windows 2016. I made it a secondary domain controller. Both servers were successfully running as Domain Controllers with Global Catalogs. I transferred FSMO roles to the new domain controller successfully. I was getting ready to demote the Windows 2003 server but it crashed two days ago. Now my ONLY domain controller says that Active Directory is not functioning properly. I am unable to add a new user, printers or even look at the Active Directory information.
What is the best way to recover my AD. I have a backup that can go back as far as 90 days. Is there any known utilities to fix/repair AD?
Thanks for your help.