We have been running a Sharepoint installation giving AD users and groups access with no problem. When viewing site permissions, we could see domain groups in the format: DOMAIN\group (c:0+.w|DOMAIN\group). A couple of weeks ago, we upgraded our domain controllers to Windows Server 2012. Since then, when we view site permissions we see AD groups as: DOMAIN\group (c:0+.w|Active Directory SID). Also, when we check permissions on an AD group member, anyone who logged into the site when the group names were showing up correctly get access to the site. Any group member that hasn't logged into the site prior to the SIDs showing up is showing "no permissions" on the site.
Any idea as to what could be causing this? We're guessing it has to do with the Windows Server 2012 DCs, but we could be mistaken. FWIW, our Production SP farm is patched to SP1. And test farm is patched to SP2. Both are experiencing
this problem.