I'm trying to grant permissions to other people to view a SharePoint site but when granting permissions it uses "Check Names" and claims any user or group that is part of a domain does not exist. It does this if I try granting permissions to the team site or in central admin BUT if I try to add someone to Farm Administrators in Central admin then all of the sudden it can find all domain users. Why is it finding domain users in that one context but not others? It is supposed to be using NTLM authentication and has Windows configured as the authentication provider (And IIS is configured to use NTLM). What's even more strange is I enabled Anonymous Access for the team site which I thought would allow anyone to view it but others say they can't access it.