We seem to have lost access to the default/builtin groups/users/OUs in Active Directory. We still have access to the custom OUs we have created below the top level domain but cannot access such things as:
Domain Admins group
Enterprise Admins group
The user we are currently logging into the DC with is/was a member of the Domain Admins group and we can access most things. We noticed this issue when we went to create a new user or reset a password for an existing user and it gave us an Access Denied error.
When we look at the AD object of this logged in user we can see the membership to the Domain Admins group but when we look at another user that was a member, all their memberships are gone.
If we highlight the domain in ADUC, in the right pane we can see the OUs but the ones we are having a problem seeing/accessing in the tree don't have an Icon associated with them.