After migrating AD from 2003 to 2012, I ran into this issue on a RADIUS server running 2008 R2, used for authentication. When attempting to retrieve AD information for a particular user, the following error appeared:

Error
An error (1301) occurred while enumerating the groups. The group's SID could not be resolved.

The solution (at least for Windows 7 and 2008 R2), is to install hotfix 2830145.

The hotfix is only available by request through e-mail.

When attempting to log on to a 2012-based domain controller, the following SIDs are unmappable:

S-1-18-1 : Authentication authority asserted identity

S-1-18-2 : Service asserted identity

2012 introduces two new securit  ...